As I read this sentence some weeks ago, I immediately felt in love with it! This is exactly what we often forget, we never should judge the worth or quality of something or someone by its/him appearance alone.
What would it bring me to have a very good-looking and rich boyfriend if he would never have time for me or would have more interest for computer games as for a talk with me. Do not worry, this has nothing to do with my own life, this is only an example;-)
You certainly know such situations where a pick-nick with simple things makes a lot of fun, and sometimes much more than a dinner in a exclusive restaurant. Or a person who is simply dressed but has much more in his/her head and heart than a well-dressed one.
And this is exactly the same with books! There are a lot of covers which do not fit to the content of the book and some covers which look "attractive" but where the content is so boring... Therefore this is always difficult when you enter a bookshop to decide which book will be the ONE.
Here an example of a fantastic book, but the editor made in my opinion a big mistake by choosing this cover and also the title of the book as this does not reflect at all the "depth" of this story.
And also there are books where the cover promises much more than it is really: