Doesn't look difficult to me...
Isn't this basically going to be like an old OHP LCD panel with a touch panel stuck on each side?
The bezel might be a bit bulky, but nothing particularly problematic.
Fitting the CPU, storage etc. into the bezel could be difficult, but depending on the device they wouldn't have to be huge. And there's always the option of having the processor remote, and connected via a cable or a wireless link.
And the software to drive everything isn't complicated.
A fully working prototype would probably be the work of a couple of weeks.
The only thing is though that this looks like it might not actually be worth doing - I suspect that while it may look cool as a tech demo, there isn't any particularly good argument for something like this - what exactly does it do better than a plain old conventional touch panel? Nothing I can think of, though I can see lots of ways it would be worse.