Blitz Icons

So I know that the little dude = non sub. That the star means subscriber and that four squared box over them means they are currently playing a games. Why do some of the icons sometimes have a little dot or bubble slightly to the above and right of them? Stupid question I know but I gotta ask. And no, this is not in the site faq so far as I could see.

I think that means they've got a provisional rating.