Yep, it's definitely a phone sized device, and you can see her scrolling with her finger in the reflection, so it's a touch screen. Now, what's actually unique about it that separates it from the millions of similar devices, I guess we'll have to wait and see. Perhaps the display stays square to your head? I mean, if you're viewing the screen at a slight angle, it skews the perspective to look straight?

http://i.imgur.com/ExL1OqV.png

There's a quick photoshop of a phone at an angle and the display square. Now, you wouldn't purposely use the phone at such an extreme angle, but when you're typing, playing games, in bed, etc, it might make things easier to use. Fairly straightforward, it would just be tracking the location of your head, and adjust the perspective of the display.

Classic geek moment. Enhance the reflection! ...When all you have to do is look down and see the whole damn thing.