Since I had to get it out of the box to photograph it, I thought I'd take my backup for a bit of a canter, and something that I'd never noticed previously. You can JUST see it in the photo you posted, the palm rest is cupped very slightly to take the ball of the palm. All my other ones are flat, but I've glued high density foam (camping mat) there, because, despite what the book says, I ALWAYS rest my hands, just using the fingers. (My hand size means that, other than the numeric keypad, I can reach every key, except, F1, F6, F7 and F12 without moving my hands from the home row.) On the backup the palm rests appear to be about an inch or so deeper as well.