(I should preface this by saying that the book mentioned below is fantastic, and I'd recommend it to everyone. However...)
Here's a book jacket design that's so bad, it's comical:
"The Great Unraveling: Losing Our Way in the New Century", by Paul R. Krugman
Look at the little "foldover" triangle at the top right of the red rectangle. What's up with that? Is it a piece of Rubylith that started to peel off the board? (for those old enough to remember.)
No, I think it's actually supposed to be a visual reminder of the title, "...Unraveling". Besides the fact that the idea is lame, cliche'd and obvious, it doesn't even make sense! That's not a picture of unraveling, for that you'd need something woven. That might work if the book was titled, "The Great Dog-Eared-ness"!