If are creating a book, or editing a saved book project, in most cases you can now change the book type and cover. 
This can be very handy if you've already created a book, but want to take advantage of a promo that specifies a different book type. Just click the Book Type icon at the bottom of the left menu to see what's available and click the type you want (note icon on right). If you don't like the change, click "Undo" to get back to your original book type.
Notes:
- You cannot change book size or orientation. Your choices are limited to book types of the same size and orientation.
- If you have created a Hardcover or Layflat book and have done any customizations to the cover, these will be overwritten if you change to a Linen or Leather book.
- Likewise, if you have a Linen or Leather cover book, and change it to a Hardcover or Layflat book, your new cover will be blank, unless you add photos and text.
- After making any change in book type, be sure to review each page to ensure everything looks right.