this is a Lemmy thread, and the behavior you’re seeing is a mismatch between how Lemmy and Mastodon handle links. on our end, it’s a direct link to the pivot-to-ai url. the version of this post federated to Mastodon links to our Lemmy instance’s thread instead, presumably to drive engagement (note that that’s not my decision as an instance admin, and I’d probably have it federate differently given the option)
this seems more like a Mastodon thing, considering that if I curl the post with Accept: application/activity+json it doesn’t have a link to the Lemmy thread, it has the link actually embedded in the post
I think Mastodon does this for other AP object types (like articles, e.g. if you put a link to a WriteFreely article into Mastodon it’ll just show the title and a link to the original post)
probably some whacky shit with how it emits the AP Post object
it’s been a while since I looked into that code but I remember it being a bit weirdly trampolined for how it pulls fields together for the final emitted object/blob