Machine learning models installed on macOS is part of Vision.framework
I found these while poking around at the list of open files for photoanalysisd in Activity Monitor.
% ls -lahS /System/Library/Frameworks/Vision.framework/Versions/A/Resources
total 465616
-rw-r--r-- 1 root wheel 40M Dec 13 16:32 landmarks_v2.bin
-rw-r--r-- 1 root wheel 31M Dec 13 16:32 scenenet_sc2.4_sa1.4_ae1.4_r9_opt_int8.espresso.weights
-rw-r--r-- 1 root wheel 29M Dec 13 16:32 scenenet_sc2.4_sa1.4_ae1.6_r13.4_opt_int8_asymetric.espresso.weights
-rw-r--r-- 1 root wheel 18M Dec 13 16:32 scenenet_sc2.4_sa1.4_ae1.6_r13.5_opt_int8_fp16-sp_ae_sa_only.espresso.weights
-rw-r--r-- 1 root wheel 18M Dec 13 16:32 scene-descriptor.bin
-rw-r--r-- 1 root wheel 18M Dec 13 16:32 rpn_template_v4.espresso.weights
-rw-r--r-- 1 root wheel 11M Dec 13 16:32 landmarkRefinerAndPupil_v2.bin
-rw-r--r-- 1 root wheel 10M Dec 13 16:32 scene-classifier.bin
-rw-r--r-- 1 root wheel 9.0M Dec 13 16:32 pumtc2j5f7_wide_u8.espresso.weights
-rw-r--r-- 1 root wheel 8.9M Dec 13 16:32 gazeflow-mcbdnde3m8_225900_opt_quantized_w_conv_u16_fc_fp16.espresso.weights
-rw-r--r-- 1 root wheel 7.3M Dec 13 16:32 combined_classification_smartCamfanet_0-0011_saliency_bhutc68tnd_aesthetics_3eqm2xn28k.espresso.weights
-rw-r--r-- 1 root wheel 7.0M Dec 13 16:32 facerec_fp2.2_fa1.1_r2_optimize.espresso.weights
-rw-r--r-- 1 root wheel 4.7M Dec 13 16:32 smartcam-descriptor.bin
-rw-r--r-- 1 root wheel 4.6M Dec 13 16:32 smartCam_v3.8.1_quantized.espresso.weights
-rw-r--r-- 1 root wheel 4.2M Dec 13 16:32 faceSemantics_v1.1.espresso.weights
-rw-r--r-- 1 root wheel 3.7M Dec 13 16:32 shotflow-8k6zuzd9wy_46860_opt_quantized.espresso.weights
-rw-r--r-- 1 root wheel 2.9M Dec 13 16:32 landmarksflow-gwkf986dmy_63053_plus_8dtz95rnyx_quantized.espresso.weights
-rw-r--r-- 1 root wheel 2.9M Dec 13 16:32 faceBoxPoseAligner-current.bin
-rw-r--r-- 1 root wheel 2.4M Dec 13 16:32 rpn_track_v4.espresso.weights
-rw-r--r-- 1 root wheel 2.0M Dec 13 16:32 face_quality_v1.0.espresso.weights
-rw-r--r-- 1 root wheel 2.0M Dec 13 16:32 scenenet_sc2.4_sa1.4_ae1.4_r9_opt_int8_pca256.pcadata
-rw-r--r-- 1 root wheel 1.7M Dec 13 16:32 bodynet_v1.0.espresso.weights
-rw-r--r-- 1 root wheel 1.5M Dec 13 16:32 faceDescriptor-current.bin
-rw-r--r-- 1 root wheel 1.2M Dec 13 16:32 6ziz6uinva_opt.espresso.weights
-rw-r--r-- 1 root wheel 863K Dec 13 16:32 junk-descriptor-current.bin
-rw-r--r-- 1 root wheel 814K Dec 13 16:32 scenenet_op-v8d.plist
-rw-r--r-- 1 root wheel 747K Dec 13 16:32 solo_landmarks_s9min6ugm8_opt.espresso.bin
-rw-r--r-- 1 root wheel 731K Dec 13 16:32 solo_landmarks_s9min6ugm8_opt.espresso.weights
-rw-r--r-- 1 root wheel 697K Dec 13 16:32 model8c_.espresso.bin
-rw-r--r-- 1 root wheel 484K Dec 13 16:32 human_3_model.adb
-rw-r--r-- 1 root wheel 258K Dec 13 16:32 faceRegionMap-current.bin
-rw-r--r-- 1 root wheel 156K Dec 13 16:32 saliency_objectness_boxes_head_ecvqeduzc7_46800_fp16.espresso.weights
-rw-r--r-- 1 root wheel 153K Dec 13 16:32 saliency_attention_box_head_i4fgq3rswb_fp16.espresso.weights
-rw-r--r-- 1 root wheel 149K Dec 13 16:32 y4w25g79av_mask2boxes.espresso.weights
-rw-r--r-- 1 root wheel 110K Dec 13 16:32 cla20k512_01f.bin
-rw-r--r-- 1 root wheel 96K Dec 13 16:32 junk_leaf.r13.j7.espresso.weights
-rw-r--r-- 1 root wheel 50K Feb 29 00:27 default.metallib
-rw-r--r-- 1 root wheel 32K Dec 13 16:32 junk_hierarchical.r13.j7.espresso.weights
-rw-r--r-- 1 root wheel 31K Dec 13 16:32 scenenet_relationships-v8d.txt
-rw-r--r-- 1 root wheel 31K Dec 13 16:32 scene-classifier-relationships.txt
-rw-r--r-- 1 root wheel 29K Dec 13 16:32 scene-classifier-labels.csv
-rw-r--r-- 1 root wheel 29K Dec 13 16:32 scenenet_labels_basic-v8d.csv
-rw-r--r-- 1 root wheel 24K Dec 13 16:32 facerec-v2.2-bgr-att-308_chk-0050__0__faceBoxPoseAligner-current__faceDetectorV2-current__ageClassifier.bin
-rw-r--r-- 1 root wheel 18K Dec 13 16:32 eigenshape.bin
-rw-r--r-- 1 root wheel 17K Dec 13 16:32 smartcam-classifier.bin
-rw-r--r-- 1 root wheel 16K Dec 13 16:32 perspective.r13.p3.0.espresso.weights
-rw-r--r-- 1 root wheel 10K Dec 13 16:32 shotflow-8k6zuzd9wy_46860_opt_quantized.espresso.net
-rw-r--r-- 1 root wheel 9.0K Dec 13 16:32 scenenet_sc2.4_sa1.4_ae1.4_r9_opt_int8.espresso.net
-rw-r--r-- 1 root wheel 6.9K Dec 13 16:32 scenenet_sc2.4_sa1.4_ae1.6_r13.4_opt_int8_asymetric.espresso.net
-rw-r--r-- 1 root wheel 6.8K Dec 13 16:32 scenenet_sc2.4_sa1.4_ae1.6_r13.5_opt_int8_fp16-sp_ae_sa_only.espresso.net
-rw-r--r-- 1 root wheel 5.9K Dec 13 16:32 combined_classification_smartCamfanet_0-0011_saliency_bhutc68tnd_aesthetics_3eqm2xn28k.espresso.net
-rw-r--r-- 1 root wheel 5.0K Dec 13 16:32 scenenet_sceneprint_r9_opt_int8.espresso.net
-rw-r--r-- 1 root wheel 4.3K Dec 13 16:32 facerec_fp2.2_fa1.1_r2_optimize.espresso.net
-rw-r--r-- 1 root wheel 4.2K Dec 13 16:32 smartCam_v3.8.1_quantized.espresso.net
-rw-r--r-- 1 root wheel 4.1K Dec 13 16:32 y4w25g79av_mask2boxes.espresso.net
-rw-r--r-- 1 root wheel 3.8K Dec 13 16:32 gazeflow-mcbdnde3m8_225900_opt_quantized_w_conv_u16_fc_fp16.espresso.net
-rw-r--r-- 1 root wheel 3.7K Dec 13 16:32 pumtc2j5f7_wide_u8.espresso.net
drwxr-xr-x 112 root wheel 3.5K Apr 20 16:39 .
-rw-r--r-- 1 root wheel 3.5K Dec 13 16:32 landmarksflow-gwkf986dmy_63053_plus_8dtz95rnyx_quantized.espresso.net
-rw-r--r-- 1 root wheel 3.4K Dec 13 16:32 scenenet_sc2.4_sa1.4_ae1.4_r9_opt_int8.espresso.shape
-rw-r--r-- 1 root wheel 3.4K Dec 13 16:32 scenenet_sceneprint_r9_opt_int8.espresso.shape
-rw-r--r-- 1 root wheel 2.6K Dec 13 16:32 bodynet_v1.0.espresso.net
-rw-r--r-- 1 root wheel 2.3K Dec 13 16:32 combined_classification_smartCamfanet_0-0011_saliency_bhutc68tnd_aesthetics_3eqm2xn28k.espresso.shape
-rw-r--r-- 1 root wheel 2.1K Dec 13 16:32 scenenet_sc2.4_sa1.4_ae1.6_r13.4_opt_int8_asymetric.espresso.shape
-rw-r--r-- 1 root wheel 2.0K Dec 13 16:32 scenenet_sc2.4_sa1.4_ae1.6_r13.5_opt_int8_fp16-sp_ae_sa_only.espresso.shape
-rw-r--r-- 1 root wheel 2.0K Dec 13 16:32 6ziz6uinva_opt.espresso.net
-rw-r--r-- 1 root wheel 2.0K Dec 13 16:32 saliency_attention_box_head_i4fgq3rswb_fp16.espresso.net
-rw-r--r-- 1 root wheel 2.0K Dec 13 16:32 saliency_objectness_boxes_head_ecvqeduzc7_46800_fp16.espresso.net
-rw-r--r-- 1 root wheel 2.0K Dec 13 16:32 shotflow-8k6zuzd9wy_46860_opt_quantized.espresso.shape
-rw-r--r-- 1 root wheel 1.6K Dec 13 16:32 face_quality_v1.0.espresso.net
-rw-r--r-- 1 root wheel 1.6K Dec 13 16:32 049c_chk-0300_1_faceBoxAligner-current_ageClassifier.bin
-rw-r--r-- 1 root wheel 1.5K Dec 13 16:32 facerec_fp2.2_fa1.1_r2_optimize.espresso.shape
-rw-r--r-- 1 root wheel 1.4K Dec 13 16:32 faceSemantics_v1.1.espresso.net
-rw-r--r-- 1 root wheel 1.4K Feb 29 00:27 Info.plist
-rw-r--r-- 1 root wheel 1.3K Dec 13 16:32 solo_landmarks_s9min6ugm8_opt.espresso.net
-rw-r--r-- 1 root wheel 1.2K Dec 13 16:32 y4w25g79av_mask2boxes.espresso.shape
-rw-r--r-- 1 root wheel 1.0K Dec 13 16:32 gazeflow-mcbdnde3m8_225900_opt_quantized_w_conv_u16_fc_fp16.espresso.shape
-rw-r--r-- 1 root wheel 1.0K Dec 13 16:32 rpn_track_v4.espresso.net
-rw-r--r-- 1 root wheel 1.0K Dec 13 16:32 pumtc2j5f7_wide_u8.espresso.shape
-rw-r--r-- 1 root wheel 960B Dec 13 16:32 bodynet_v1.0.espresso.shape
-rw-r--r-- 1 root wheel 935B Dec 13 16:32 perspective.r13.p3.0.espresso.net
-rw-r--r-- 1 root wheel 915B Dec 13 16:32 rpn_template_v4.espresso.net
-rw-r--r-- 1 root wheel 854B Dec 13 16:32 landmarksflow-gwkf986dmy_63053_plus_8dtz95rnyx_quantized.espresso.shape
-rw-r--r-- 1 root wheel 844B Dec 13 16:32 6ziz6uinva_opt.espresso.shape
-rw-r--r-- 1 root wheel 830B Dec 13 16:32 smartCam_v3.8.1_quantized.espresso.shape
-rw-r--r-- 1 root wheel 643B Dec 13 16:32 saliency_attention_box_head_i4fgq3rswb_fp16.espresso.shape
drwxr-xr-x 20 root wheel 640B Dec 13 16:32 Wisdom
-rw-r--r-- 1 root wheel 626B Dec 13 16:32 face_quality_v1.0.espresso.shape
-rw-r--r-- 1 root wheel 612B Dec 13 16:32 saliency_objectness_boxes_head_ecvqeduzc7_46800_fp16.espresso.shape
-rw-r--r-- 1 root wheel 592B Dec 13 16:32 junk_hierarchical.r13.j7.espresso.net
-rw-r--r-- 1 root wheel 581B Dec 13 16:32 junk_leaf.r13.j7.espresso.net
-rw-r--r-- 1 root wheel 508B Feb 29 00:33 version.plist
-rw-r--r-- 1 root wheel 482B Dec 13 16:32 solo_landmarks_s9min6ugm8_opt.espresso.shape
-rw-r--r-- 1 root wheel 481B Dec 13 16:32 faceSemantics_v1.1.espresso.shape
-rw-r--r-- 1 root wheel 465B Dec 13 16:32 rpn_track_v4.espresso.shape
-rw-r--r-- 1 root wheel 427B Dec 13 16:32 smartcam-classifier-relationships.txt
-rw-r--r-- 1 root wheel 427B Dec 13 16:32 smartcam_relationships-v3b.txt
-rw-r--r-- 1 root wheel 417B Dec 13 16:32 smartcam-classifier-labels.csv
-rw-r--r-- 1 root wheel 352B Dec 13 16:32 rpn_template_v4.espresso.shape
-rw-r--r-- 1 root wheel 334B Dec 13 16:32 perspective.r13.p3.0.espresso.shape
-rw-r--r-- 1 root wheel 256B Dec 13 16:32 junk-classifier-current.bin
-rw-r--r-- 1 root wheel 250B Dec 13 16:32 scenenet_aesthetic_labels_basic-v8e.txt
-rw-r--r-- 1 root wheel 208B Dec 13 16:32 smartcam_labels_basic-v3b.txt
-rw-r--r-- 1 root wheel 204B Dec 13 16:32 junk_hierarchical.r13.j7.espresso.shape
-rw-r--r-- 1 root wheel 197B Dec 13 16:32 junk_leaf.r13.j7.espresso.shape
-rw-r--r-- 1 root wheel 173B Dec 13 16:32 junk_leaf.labels_basic-v2e.txt
drwxr-xr-x 5 root wheel 160B Apr 20 16:39 ..
drwxr-xr-x 3 root wheel 96B Jan 23 03:12 BridgeSupport
-rw-r--r-- 1 root wheel 71B Dec 13 16:32 junk_hierarchical.labels_higher_order-v2e.txt
lrwxr-xr-x 1 root wheel 55B Apr 20 16:38 scenenet_sceneprint_r9_opt_int8.espresso.weights -> scenenet_sc2.4_sa1.4_ae1.4_r9_opt_int8.espresso.weights
-rw-r--r-- 1 root wheel 26B Dec 13 16:32 perspective_labels-v1a.txt
-rw-r--r-- 1 root wheel 4B Dec 13 16:32 junk-classifier-labels-current.txt