So this is a valid point (and I admit I eat crow on my earlier statement), but not for that reason. In that photo, there are three fingers in front of the cup, but you would not expect 5 fingers because the way humans hold cups, the thumb will be occluded by the cup itself. That said, I don't think there is a way to hold a cup with both thumb and index occluded, so the correct number of fingers would be 4 in that case.