The real question is: if mods don't want regular members to know about the existence of those accounts with special privileges, why they let them wear avatars?
Maybe, they made a trial and forgot to take those avatars off.
Last year, I saw a project that the team decided to wear new signature (re-designed) before opening of new wave, then they forgot to take it off.
It's just an assumption, and still need official answers from theymos or staffs.