When looking at all of these covers for different books, i can say that every design for the spine is nearly the same with large text at the bottom or middle and with a authors name on it or a little logo indicating the book. Also when looking at the designs for the back cover, some are different from others. Like some books doesnt even have a blurb on the back and others do. But the books that have the blurb are normally placed differently like you got some blurbs that are aligned centred and you got others aligned on the left side. Another thing that u can sometimes see on the back cover is that you can normally see a paragraph and a picture about who the author is as well as you can normally see a barcode and the book manufactures. Sometimes on the back cover design to make it look a bit more interesting and not just bland, there is normally a background image that would slightly catch the audience’s eyes and sometimes there is a picture of the author behind the blurb.
Every design is completely different. You can hardly find a design that is normally exactly the same except if its a series of the same book types.