Add Pods Admin based images in your template file

oxygen-pods-gallery-loop.php

<?php
  // use class .gal-single for additional styling
  // get pods object
  $custom_field_name = 'custom_portlofio_gallery';
  $mypod = pods( $post->post_type, $post->ID );
  if ($mypod->field($custom_field_name)) {
    foreach( $mypod->field('custom_portlofio_gallery', true) as $picture) {
      echo '<div><img src="' . $picture['guid'] . '"  class="gal-single" width="100%" height="auto" alt="' . $picture['post_title'] . '" /></div>';
    }
  }
?>