It’s curious that it doesn’t look very different from the final product, it is obviously thicker but everything was thick in 2002! I also love the milky white plastic. I wish Apple hadn’t abandoned it, it was a distinguishing factor from the rest of the hardware makers. The aluminium still feels very cold to me, specially on the iPad.
This also proves that Apple have been fiddling with touch screens for a really long time, and they only got it right 8 years later, on a much smaller form factor.