UI differences are a big factor in the success/failure of decentralised federation of diverse platforms and content
And this seems a good example: bridged #mastodon posts onto #BlueSky which has a lower character limit than Mastodon.
So, just like #lemmy posts on mastodon, you don’t get the full content of the post (which ends with an abrupt ellipsis here) and have to take a link to the original platform.
However powerful the underlying protocols, this isn’t far from screenshots.
IMO bridging or translation isn’t federation per se. Also it seems unlikely that protocols would converge to that extent. In fact AP implementations are already different enough that even within the same protocol it’s hard to represent all the different activities instances can present.