Saved books appear as special collections in the Collections panel.
To add a photo to the saved book, drag the photo or photos from the Grid view in the Library module and drop them on the Saved Book Collection. When you click on the saved book collection, the photos you dragged should be available there. You can do this many times.
Cesidio Di Ciacca
thank-you as well! I had the same issue!
Awesome, thanks. So simple.