Hey @peternlewis,
I'm having the same problem.
I can't see my own profile picture either in-line in threads OR in the user-menu (top-right) in Google Chrome.
In Safari I can see my own profile picture for both threads and the user-menu, but I can't see some other people.
After deleting Safari's cache I'm having the same problems with Safari.
For example:
In the following thread @LesB's profile is invisible to me in Safari
Can I Create Macros for Inserting Date and Time?
Everyone is invisible to me in that thread – including my profile pic in the user-menu.
I have restarted Safari and Chrome, and I've deleted their caches.
I just tried in a newly updated Firefox, and I can see my own profile but not Les'.
Something is clearly amiss...
-Chris