Warning: This solution isn’t pretty.
By default there’s no clean way to list all the Docker images in a remote docker registry, especially if you’re using SSH without a keypair or certificate of any kind (as is the case in my setup, yay!).
Instead you have to first query the registry API _catalog endpoint to get a list of all the repositories, and then run separate queries on each of the repositories that were returned to list all the images.
Ergo this monstrosity:
ssh -t user@host.goes.here '
for repo in $(curl --silent localhost:5000/v2/_catalog | jq -r .repositories[]); do
curl --silent localhost:5000/v2/${repo}/tags/list | jq .;
done;'