I actually think the arm is real(made out of cardboard) because there are certain transparent parts(the scope and dangles on the end). That, or the arm was photoshopped in very well.
tengen said: It's not photoshoped. It's not a full sun, probably partially cloudy. So the shadows aren't too distinct and defined. But it does have shadows.
You are correct. Also note the shadow of the person's foot in the background (the one with the olive-gray cargo pants). It's coming toward the camera, if not, slightly to the right. Even on a sunny day, the shadow would fall out of frame.