If you use the Quote feature they can.

I see quotes as the most interesting aspect of highlights; is where you can express your thoughts about something that you considered valuable.

For a while I was calling these Margin Notes. To me this also fascinating:

when a friend lends you a book be a use they think you would appreciate it, if the book has your friend’s margin notes on it that’s the first thing you’d read.

It’s the intersection between someone you care about and a thought provoking book.

But I digress: Quotes help with this; more clients are giving a more central role to highlights too which should also help.