Icon Help?

I feel like an idiot for asking for help with what I suspect is a simple technique, but I can't seem to pull it off.

Do any of you know if there is a tutorial, or could give some tips on how to make images like this:


(by littlekari @ jujubas)

How the everything around the figure is sort of bathed in black? I don't know of any other way to explain it. I'd left a comment on the entry where I found this, but got no response.

I use Photoshop CS.

Thank you for any help!