UPDATE: Looks like its a bit more complex (isn't it always)
So the CTO is here at @jsecretan and has clarified that they are in the process of implementing bidirectional #ActivityPub, but in the meantime ingested the "federated timeline" of Mastodon.social
You can look at their AP response here: https://staging.maven.ly/mastodon/actor/1 though it doesn't seem to be live on their main domain.