This is visually interesting, but I can't help but feel that doesn't mimic the experience of browsing in a library. It prioritizes book covers that distract the eye (and strain it, being thumbnail-sized). I remember feeling the same way when Apple showed off skeuomorphic bookshelves on the iPad(?).

Are the various scanning projects (inc. The Internet Archive's own) failing to photograph spines? The screenshot of the 3D view in this post shows computer generated spines. Trying things out in the explorer, there's another "3d-spines" view that's similar (and a "spines" view that doesn't seem usable at all, but maybe that's a bug caused by browser differences).

The ideal interface IMO would mimic eyeballing a shelf of spines without the requirement of tilting your head 90 degrees (unless you wanted to, I guess). I'm thinking of a fullscreen interface that resembles the "3d-spines" view, but it lets you drop into a narrow focus on a single shelf, with a stack of proportionally correct scans of real spines that take the full width of the screen, with the hint of the cover in the gaps superimposed by uniformly typeset labels.