A rectangular photo book is a landscape or portrait album, not a square Instagram book and not a trading-card binder. Travel, family, and wedding photographers pick 8.5x11, 11x8.5, or smaller 6x4 / 9x6 rectangles so wide shots keep their horizon. Binding, paper, and cover finish decide whether it lives on a coffee table or in a bag.
Count pages and paper weight before you upload. A 20-page press book is a different object from a 1 mm layflat wedding album.