When I loaded the review page (in Stack Overflow, though I have no specific reason to think it is related) I got a weird hat in the upper left hand corner.
See the hat in the upper left hand corner? That's belonging to user # 3651800. His profile page also has the hat in a ... weird ... location, but not this weird.
I'm guessing this is due to the not-loaded image for the avatar (adblock blocks Facebook avatars for me often)? It also causes the toolbar notification to show his link unless I'm hovering over something else. It also changes the location of the gray box to the upper left hand corner when I hover over the hat (and hovering over the white box does nothing).
It's definitely him (or any not-loaded avatar perhaps), once he fell off the last 6 reviewers it stopped appearing.