Inside a share extension on iOS you can extract the original HTML and CSS. Maybe Damus parses the html from the note and displays it in a web view? I do similar things in @npub1m3px...zh0j Contex.st

Highlights are a separate event kind. Kind 9802, specifically. Not all clients support all event kinds, nor should they. That said, I think it makes sense for major kind 1 clients like Primal to also support highlights, as people naturally want to share quotes they found interesting with their followers and spark discussion around them without their followers needing a separate app to see the highlight. Highlights are also really nice to use within a long-form article. I think I have a highlight in one of my articles. I wonder how Primal reads handles it... Highlighter.com also supports highlights, as does Amethyst on Android.

Ha! Not well, apparently... This is from my article with a highlight quoting a paragraph from an article by @ hodlbod as displayed by Primal:

🤷🏽 That’s outside my area of expertise. lol

I agree! I like the way highlights are presented. It’s easier to share the quote by highlighting instead of taking a screenshot then sharing. I just learned about it as I was perusing the share sheet. I was trying to share a passage.