I understand. It really comes down to your entry point. For example, as long as I’m viewing the community/user/content via my instance I can interact; e.g. I’m replying to a post on mylemmy.win/post/114914 ; you, on the other hand are replying to kbin.social/…/why-can-t-we-have-federated-identit… . Since we’re viewing from our own instances we can interact. If either of us goes directly to the canonical URL, lemmy.world/post/1194109 , we’d be forced to login. It’s all the same post, just different points of entry that muddy the user experience.