Just played with it. I was intrigued by the sign-up process - it only asked for my first name and photo. Is it doing something magical to tie my'account' to my

Just played with it. I was intrigued by the sign-up process - it only asked for my first name and photo. Is it doing something magical to tie my'account' to my name and photo? Or is the user name a much 'looser' association and not something you have a strong hold over?