TOPIC: Mobile selections

Why when I select a comment on mobile and THEN change the comment is it changed on the non selected side? I think that it should work like it does on the desktop version. When the comment is black, if you make a change, it should change it to the black (non selected comment). But when you tap once for green, and twice for red, THEN make a change, it should only change the selected version of that comment. Is there a reason that it does it the other way, or am I doing something wrong?