The understanding of theft: one refers to the possession of the book itself, and the other refers to the use of books to seek economic benefits.

If the bookstore forbids you to browse, taking pictures is stealing. If you don't forbid browsing, it means that you are not forbidden to read the memory for free. Of course, taking pictures as an auxiliary memory is not prohibited.

Relevant laws and regulations:

According to the provisions of Article 22 of the Copyright Law of People's Republic of China (PRC):

For one's own study, research or appreciation, one may use the published works of others without the permission of the copyright owner, or pay no remuneration to the copyright owner.

As long as it is not used for commercial purposes or to expand the scope of use, it is not illegal for readers to shoot books.