Fair use is a doctrine in United States copyright law that allows limited use of copyrighted material without requiring permission from the rights holders, such as use for scholarship or review.
The "useful article" provision at 17 USC 113(c) states:
- "In the case of a work lawfully reproduced in useful articles that have been offered for sale or other distribution to the public, copyright does not include any right to prevent the making, distribution, or display of pictures or photographs of such articles in connection with advertisements or commentaries related to the distribution or display of such articles, or in connection with news reports."
Which means that for purpose of commentary (ie: reviews and such) a picture of the cover of a book is not protected by copyright. (Actually, this is not technically "Fair Use", which is defined in paragraph 107, but another provision) The same goes for pictures of other equipment, like boards and stones.
Important: This does not mean that any picture of a book cover or go board on the internet is free to use! Although a book publisher cannot claim copyright on a picture of one of his books, the photographer can. So pictures that you have taken yourself are okay, pictures taken by others may not be.