I’m not sure when Amazon began doing this but they’ve made it easier to share items from the iOS app. I just happened on this “trick” the other day when I wanted to share a book and its price with a friend. Once you take a screenshot a share button appears that you can now share it through the share sheet. It also will include a link to the book as well. I’ve found this helpful not only sharing books with friends but also adding a list in Evernote or my task manager to look at later.