As you see, the video shows a digital pop-up book. It's a demo for Between Page and Screen, a new book that has just been released.
The gimmick here is that the pop-up words are poems that are sent between 2 lovers. You hold the book in front of your webcam and you'll be able to see the poems on your screen. If you want to see it in action, there's a sample that you can try.
I like the idea but I don't think this implementation works all that well.
I tried the sample, and I found that I had to hold the sample at a minimum of 30 degree angle for it to work. The demo video above fudged a number of details; I could not hold the sample as flat as that book was held. It stopped working when I tried.
The angle and position of the sample wasn't terribly convenient. I did eventually figure out where to position it between me and the screen, but the book wouldn't be as convenient.
But don't take my word for it; go try it. It's worth a few minutes of your time.
All in all, I like the idea, just not this particular book. But I recall seeing something similar back in 2010. That book was called The Search for Wondla. It seemed to work better, so I'm going to go get a copy and try again.