Being able to fold down a larger "sheet" display so that it fit in a pocket would be pretty cool. Having extra room for reading things like maps and comic books is so much better than pinching and zooming on a pocket sized display. What you call limited purpose, I call functional design. I'm kind of over all-in-one devices. They've turned into Jack of all trades, but master of none.

Obviously that's not what this device is, but it got me thinking about why I'd want a device with multiple e-ink displays or a foldable display.