Many gravure idols post "off-shot" (behind the scenes) photos that didn't make it into the final book.
often include "Look Inside" features or sample images of the book's layout and style. Digital Archives: Internet Archive Gravure Photobook Free
Services like Kindle or Rakuten Kobo frequently offer "Free Trial" versions or "0 Yen" booklets. These are typically shortened versions of the full release, designed to give readers a taste of the photography style. Many gravure idols post "off-shot" (behind the scenes)