I remember a viral post on Twitter from someone listing nothing but complaints about Mastodon/federation which was written after the big furry instance, snouts.online, imploded. This was a few years ago. I’ll admit it made me skeptical about the fediverse, but after actually trying it out for myself it’s not as bad as that thread made out. Might be that that thread is still in the back of people’s minds when they consider twit alternatives.

Hah! Searching images with text is nearly impossible, but I did see a Martok image about doing battle against depression.

Christopher Judge

I'm following the furry community on yiffit.net using my mastodon account, and I saw a post show up on my mastodon feed. So I opened up the thread in another tab, and I've been faving/unfaving the mastodon post... and the score on Lemmy goes up/down immediately. So yeah, it looks like faves from mastodon are translated into upvotes on Lemmy.
I've also seen likes on my PixelFed notifications come in from Kbin.social users on this post that I sent to Lemmy from there - I'm assuming those were upvotes on their end.

I'm now thinking that some of the upvotes on that thread are actually likes and shares from mastodon. Edit: this might only be the case for new posts.