Wait, the books are the angels?

While watching Wings of Desire (the movie City of Angels is based on), I pondered that the metaphor for invisible angels hanging out at libraries was that the books are actually the angels themselves...in book form.

An angel appearing right next to a reader happens because they are being brought back to life. Someone is reading their book and the book is serving as a form of help from the angel to the person reading.

It’s also possible it simply means angels (who metaphorically live in the sky and are not physical on Earth) are just feeding off the brainwaves of the readers while they are reading, using their minds.