I refreshed my page a while ago and saw that my username in the top right was belonged to someone else, and the profile picture was wrong. I checked my profile and everything seemed fine but the drop-down in the top right still had the other user and pfp. When I appended their user ID to the URL bar, I found their profile and it had the pfp that was showing on my end.

I posted and it worked fine, my user was attached. Just a weird visual glitch? Saying it for the sake of saying it :p