Definition: A shelf on which books can be stored.
Classifier phrase: Lots of books on a shelf.
The left (passive) handshape is a classifier, representing a book. The right (dominant) handshape (claw) is a classifier, representing 'lots', 'abundant', and such. The movement from left to right shows a plural.
Pluralization: a set of books on the shelves; a lot of books on the shelves.
The movement of a dominant hand from left to right twice represents a plural of both books and shelves.