I tried clipping the image of the toot I wanted to share...uploaded the image....and then added comment above. It worked :)
Maybe some good folks here know another way?
@1_Mind_Traveler And you mentioned the original account, too?
@Beanc @1_Mind_Traveler The user's handle would be visible in the screen shot, but I was asking if they'd be mentioned as well, so they can choose whether or not to participate in the discussion.