Hi
Unfortunately, SimCity players have had an issue getting the profile picture to show up or change in the game. I have heard that this is because the avatars only update when the game is patched, and since the game is no longer actively developed, it will not be patched again (so no avatar). I'm still trying to get some official verification of this, but it does seem likely this is the problem.
I agree with you - I don't want to see a question mark on my avatar every time I play either.