vncserver exited on container startup

[xfudox]

Just tried retroarch following docker startup docs:

$ docker run -v /path/to/roms:/roms -p 8003:80 blaize/retroarch
2025-03-04 10:41:22,765 CRIT Supervisor is running as root.  Privileges were not dropped because no user is specified in the config file.  If you intend to run as root, you can set user=root in the config file to avoid this message.
2025-03-04 10:41:22,768 INFO RPC interface 'supervisor' initialized
2025-03-04 10:41:22,768 CRIT Server 'inet_http_server' running without any HTTP authentication checking
2025-03-04 10:41:22,768 INFO supervisord started with pid 1
2025-03-04 10:41:23,774 INFO spawned: 'audiostream' with pid 7
2025-03-04 10:41:23,779 INFO spawned: 'nginx' with pid 8
2025-03-04 10:41:23,781 INFO spawned: 'pulseaudio' with pid 9
2025-03-04 10:41:23,784 INFO spawned: 'vncserver' with pid 10
2025-03-04 10:41:23,786 INFO spawned: 'websockify_audio' with pid 11
2025-03-04 10:41:23,788 INFO spawned: 'websockify_vnc' with pid 12
2025-03-04 10:41:23,802 INFO success: nginx entered RUNNING state, process has stayed up for > than 0 seconds (startsecs)
2025-03-04 10:41:24,824 INFO success: audiostream entered RUNNING state, process has stayed up for > than 1 seconds (startsecs)
2025-03-04 10:41:24,824 INFO success: pulseaudio entered RUNNING state, process has stayed up for > than 1 seconds (startsecs)
2025-03-04 10:41:24,824 INFO success: vncserver entered RUNNING state, process has stayed up for > than 1 seconds (startsecs)
2025-03-04 10:41:24,824 INFO success: websockify_audio entered RUNNING state, process has stayed up for > than 1 seconds (startsecs)
2025-03-04 10:41:24,824 INFO success: websockify_vnc entered RUNNING state, process has stayed up for > than 1 seconds (startsecs)
2025-03-04 10:41:24,832 INFO exited: vncserver (exit status 0; expected)

Then, viewing localhost:8003 I get a simple directory listing:

Am I missing something?