Technical explainer:
https://github.com/RupertBenWiser/Web-Environment-Integrity/blob/main/explainer.md#how-it-works

It apparently requires some kind of proprietary operating environment to function, thus making it compatible with free (as in freedom) computing. You would need either a proprietary library/OS or an open OS but a proprietary piece of vendor hardware to act as the attester.

I've followed my fosstodon account on kbin.social and my kbin.social account on fosstodon and I'm unable to see posts in either direction. It doesn't seem like cross-interaction is working at the moment to me.

WAIT. I'm actually half wrong. I can see my kbin posts from mastodon! It's just that they're all comments so far, so I have to go under the "Posts & Replies" section to see them. However, I'm still not able to see my mastodon posts from kbin.

I'm actually half wrong, posted an update.

@Otome-chan@kbin.social Alright, thanks, I have noticed posts from Mastodon showing up here. What I still don't understand: How do posts from the fediverse get sorted into Magazines on kbin? And what is the difference between articles/threads and microblog posts, in terms of the ActivityPub protocol?