Having seen numerous medieval churches in France, it struck me that their purposes were not the same as those used by today's churches. Many (most? all?) were built like defensive forts and their halls seem too big to house Sunday meetings of the surrounding population.
Without going into what I've been discovering (for simplicity's sake, you can Google "medieval church" for references), this picture book definitely does add to understanding, or else, leads to more questions (which, when you are interested in history, are fun).
The title is like, way brilliant. It is far more titillating than the book, for sure. What you'll be seeing are pictures of ancient church facades that feature exaggerated male and female gentalia.
The historians involved in this research have not been able to draw conclusions about the imagery. Were they warnings, enticements, or good luck/fertility symbols? Obviously, people regarded their bodies differently in the distant past, especially when you consider that nudity was often the norm when environmental protection wasn't needed. Note that soldiers often went into battle pant-less and erect penises are used as symbols for guideposts and warnings throughout Europe and Mediterranean countries, if not beyond.
Anyway, buy the book and try not to be embarrassed when visitors see it on your coffee table . . . better yet, flop it on your office desk and see if anyone nails you for what is, essentially, our historical past.