Not your father's M-16

Found this picture in USA Today:



I see small elements of the M-16 in the muzzle and the little flap the spent brass flies out of. You know, the thingie. But what the hell is all that other stuff?

You can click the picture for a bigger image. By the way, the soldier is identified as Sgt. Christopher Parks, in Baghdad. Found the same picture here, where it also says he's from Washington DC.