@db0 on Mastodon it just boosts the posts, I assume that's what Lemmy also does in addition to copying it and formatting the data as a post.

If I oversimplified or got that wrong I'd definitely appreciate if @dessalines or @nutomic could correct me on that. As far as I know there doesn't seem to be a reason why the same post can't appear simultaneously in multiple communties, since they're just boosts and duplicates on the federated instances. @lemmy_support