Strange docker inspect behavior

docker_inspect

docker inspect fuel/nailgun_6.0:latest

    "config": {
        "Hostname": "f218e5ce70a0",
        "Domainname": "",
        "User": "",
        "Memory": 0,
        "MemorySwap": 0,
        "CpuShares": 0,
        "AttachStdin": false,
        "AttachStdout": false,
        "AttachStderr": false,
        "PortSpecs": null,
        "ExposedPorts": {
            "8001/tcp": {}
        },
        "Tty": false,
        "OpenStdin": false,
        "StdinOnce": false,
        "Env": [
            "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
        ],
        "Cmd": [
            "/bin/sh",
            "-c",
            "/usr/local/bin/start.sh"
        ],
        "Image": "2282543ce125ce1fc5307b65a31a9d5314fe9e62c848ba9db6fb3e5cc073c157",
        "Volumes": {
            "/etc/nailgun": {},
            "/usr/share/nailgun/static": {}
        },
        "WorkingDir": "/root",
        "Entrypoint": null,
        "NetworkDisabled": false,
        "OnBuild": []
    },


cat config.json  | python -m json.tool | less

    "Volumes": {
        "/etc/fuel": "/etc/fuel", 
        "/etc/nailgun": "/var/lib/docker/vfs/dir/672810edc6a1eb8690f2de3533729305b75b909b7c9616bcac0bd2b65efdcbde", 
        "/root/.ssh": "/root/.ssh", 
        "/usr/share/nailgun/static": "/var/lib/docker/vfs/dir/d2e973580cb991d0e67143011db3d9078a8d3c311f52396da375bed3831ab880", 
        "/var/log": "/var/log/docker-logs", 
        "/var/www/nailgun": "/var/www/nailgun"
    },