Something like this. Probably have the username equal size as note text, or maybe have not text actually smaller, as the notables here are the rection, and the usernames. Maybe with a smaller version of the pfp in between?

But no idea how tricky this would be. It's an aggregated view, so it's also tricky to combine this with the view. Timestamp would be last reaction, so a viral thing would keep bubbling up. One way would be to cap it at a fixed number of reactions, and if it overflows, you would get a separate aggregated reaction note.