@Wild_Mastic yes, this is someone replying from mastodon. By default it adds ats for the thread and all comment parents to my post, but I can delete them.

I got here by finding this comment on the lemmy.world website and copying the URL into my mastodon client manually. If I wanted to spend time here specifically, I could get a feed of all your posts by following @Wild_Mastic, follow all posts from this sub magazine as if it were a user reblogging all content in it by following @main. I think there is also a way to follow any post to the instance but that would be something of a firehouse of information.

Regrettably, there is no great way to easily post with a nonlocal non-lemmy/non-kbin account to my knowledge currently outside of subscribing to these places prior to the post being made that you want to comment / interact with. But that could be done either with improved apps on desktop / mobile, integrations from existing apps or even something like a web browser addon perhaps.