You get an upvote for “whatever that is”, because it’s annoying as hell when people post stuff with no background and assume the entire world know what they’re crying about.
That’s why I was tongue-in-cheek mocking mastodon users who accidentally post to Lemmy. OP wasn’t trying to start conversation, they were posting a random thought into the ether.
Ah, I see, you posted it a few minutes before me, while I was still researching the correct link. It’s funny that they declare this feature as “experimental”, because it’s not supported by Firefox and this document is from Mozilla. I hope they will support it soon, because this looks like a cool feature. And yes, Firefox is my favorite browser (since version 1 back in the days).
The View Transitions API doesn’t currently enable cross-document view transitions, but this is planned for a future level of the spec and is actively being worked on.