So, I was experimenting a bit with inter connectivity from different ActivityPub softwares. And turns out that emoji-reaction on calckey (a microblog software that is NOT mastodon) is converted to an upvote.
So I can literally angry upvote posts on lemmy! That’s pretty cool.
Edit: on another note, posts with multiple pictures don’t federate very well with lemmy. Edit does work though
They probably want to jump on the Fediverse hype bandwagon so it does not eventually leave them and their corporate interests behind... which is exactly what the Fediverse is trying to do so I'd ignore their attempts.