here's one thing I noticed first off - the books look very much like pop culture books - let's say the shapes and sizes and colours of books do not seem as "serious" as the library - they resemble typical shelf books found in bookstores in shopping malls ..
I would expect more "serious looking" thick brown, bound in leather books, not that much colorful like a bunch of cook books - I know it's actually judging books by their cover (and size) - but that's just a first thought when looking at the render - you know, you need some bibles, encyclopedias, philosophers, famous dead writers

.. make them dark colours, dark red, brown, black, and thick