The physical display of the virtual bookshelf is one of my wishlists and this is my comments when ArtFrame was discussed in HN last month [1].

Perhaps if you can make the book width in proportion of the book's number of pages it will be great. Well done for the software, will try this soon.

[1]ArtFrame: E-paper wireless artwork for your living room:

https://news.ycombinator.com/item?id=30839762