Idea: Highlight Reaction

Allow users to highlight part of a message and click "Add Highlight Reaction..." then pick an emoji.  Shows an emoji with a plus on it, where the person who posted can click and see what part of a post someone likes or dislikes specifically. (Same screen as the "Reactions" list modal: User name, colon, text highlighted.  Mouseover if it's more than one line so other users don't get pushed out.)  If a user highlights an entire post, "Highlight Reaction" should hide to just tell the user to set a normal reaction.

Nitro required to do it, anyone who writes a post can see highlight reactions made by Nitro users.