As it's using one screen, is there any reason they didn't make the lower touch area the same size as the upper? Couldn't they have just scaled up, or is the ratio wrong?
Generally with an LCD screen, you need to be able to scale up by a natural-number factor, or the image comes out looking like total blurry ass. The bottom screen is 320x240, so you'd need at least 640x480 to scale up by doubling the dimensions. And even if it were possible, for both screens to be the same physical size, you would need two separate screens that have completely different DPIs.
So it's basically doomed to forever look a little bit weird with two differently-sized screens.
(Incidentally, I think it's still a real possibility that these things are using Wii U Gamepad screens. A Gamepad screen flipped on its side would have a resolution of 480x854, and the top screen needs to have a horizontal resolution of 400 pixels. We know that they're already masking off unused sections of the middle and bottom of the screen to create the illusion of having two screens - how hard could it be to mask off 40 pixels on either side of it in addition to that?)