
In the first comment in the above image, Chris's username is highlighted, because he is the original question asker. Sam's comment however, looks like anyone else's, despite being the answerer. While in the case of this particular comment chain, it doesn't really matter who is replying to Chris, in others, especially longish chains, it can get confusing who is the asker, answerer, and chimer-inners. Perhaps something minor, such as underlining it?