The book isn't just instructional; it's an essential ingredient in the recipe you're following. The pages of the book are made from fresh pasta and as you read the book you use the pages as sheets in preparing a classic lasagna. At the end of the process you're minus a cookbook, but you've gained a delicious meal.
After following the recipe you end up a meal you can serve and eat, and you didn't have to worry about getting the pages of the book dirty, or where you'll store the book when you're done.
As PSFK points out, by using the book as an ingredient in the dish itself, your expectations of the cookbook format are expanded.