In this view:
The thread starter is the avatar displayed.
Would it be useful to have the avatar displayed be the avatar of the last person whom responded ?
Uses:
(1) Support conversations .... if you don't see your own icon ... then you might want to look at that conversation ... to make sure they haven't asked any new questions.
(2) The inbox above shows a new reply to a conversation. If the avatar changed, then I would know visually who replied. I guess you can read the micro writing.
[Susan in this case]