It seems like when I press it it does the same thing that
It links to the fediverse instance from which the post or comment was originally made. If you click this icon on this comment it will take you to lemmygrad for example. The comment originated from lemmygrad from which it was federated to whatever instance you are now viewing it from.
so, i've gathered by clicking it that it sets lemmy from dark mode to light mode and makes emojis huge
what a useful button
The intent is to allow the reader to view the comment as intended. From one Lemmy instance to another it makes little difference, but from Kbin to Lemmy, Firefish to Mastodon, etc. there can be differences in things like Markdown, image embeds, and the availability of other contextual features like "quote tweets."
For instance, Hexbear does not allow externally hosted images to be embedded in comments. If someone from another instance makes a comment like this, you might use this button to view it with the embeds enabled.
Another example, on Mastodon sometimes large media files don't get mirrored, and you need to use this function to watch an attached video.
IMO, it should be buried in the hamburger menu.
porkroll, I love you and everything you do - and I get if you knew what was happening and were just adding more contextbut i was doing a bit
It means that the post comes from a Lemmy instance that isn't your home instance. The link takes you to that instance. Or at least it does that on the main page. On comments? No idea.
Some quick testing suggests that for comments it's a direct link to that comment exactly, while the chain icon is a link to the context.
