Looking at the device from the side, you can see the Magic Trackpad's Multi-Touch surface--the darker gray layer onto of the shinny aluminum frame. This surface is help onto the frame with adhesive. To remove the surface, I would need to heat the adhesive. As this would likely damage the device beyond repair, I'm going to leave the surface in place.
Besides, there's nothing really to see on the underside of the surface other than adhesive. You can see much of the touch surface's underside through the internal support structure.
Photo credit: Bill Detwiler / TechRepublic