This book tells me how a a character feels and acts under the influence of certain emotions, including body language and facial expression.
I've long wished for a book like this.
There have been books and classes before telling writers about character emotions, but those haven't been as helpful. Typically, those books and classes get it the wrong way round: they tell how to read body language (if a character's posture looks so-and-so, it means he's feeling such-and-such). As a writer, I found those useless. I know what my characters feel; I want to know how to convey this to my readers.
For years, I compiled my own list of emotion details for my own use. The material I've come up with has been helpful but limited. I'm glad someone has finally published a book with all the information, much more comprehensive than what I've come up with, and structured the way writers need it. The writer can look up the emotion, and see how it feels physically (useful when the character is the PoV) and how it looks to someone else (posture, facial expression, movement etc - useful when the PoV observes that character).
I recommend this book for professional level writers.