I kept thinking, "How on earth did they DO this?"
And the creators explained it:
After organizing our bookshelf almost a year ago (http://youtu.be/zhRT-PM7vpA), my wife and I (Sean Ohlenkamp) decided to take it to the next level. We spent many sleepless nights moving, stacking, and animating books at Type bookstore in Toronto (883 Queen Street West, (416) 366-8973).
Very, very cool.