I don't get it
Lantern, a browser extension for highlighting and annotating webpages: https://chromewebstore.google.com/detail/lantern/jjoijlenmgefkaeiomoaelcljfibpcgh
This is very hard to do but it actually works since it is a fork of the long-established hypothes.is extension, only changed to be compatible with NIP-84 and NIP-73. Thanks nostr:npub1dejts0qlva8mqzjlrxqkc2tmvs2t7elszky5upxaf3jha9qs9m5q605uc4 for the initial forking work.
Here it is rendering an annotation made by nostr:npub1xsp9fcq340dzaqjctjl7unu3k0c82jdxc350uqym70k8vedzuvdst562dr somewhere else I have no idea where:

It even works on PDFs:

Even though it works it definitely has bugs, so bug reports are appreciated (by "bug report" I mean just replying here). Thank you.
Discussion
what don't you get?
How when why do I use it?
How: Install the browser extension.
When: Whenever you want to easily record or share a passage from a website
Why: Because you want to do the above.
Copy ya idk why I have trouble understanding highlights.... What's the legacy social media comparison??
maybe something like Medium? I think they have highlights that you can share or comment on (within their walled garden, of course)
Which browser extension?