The author, herself an analyst, gives an intimate picture of how Winnicott conducted her treatment, how he interpreted, how he offered her a holding environment, how he dealt with anger (his and hers), and how he helped her recover from a deep, cataclysmic depression.
It is a book about a relationship between analyst and analysand in the context ot psychotic anxiety and regression to preverbal states and not a book on psychoanalytic theory. It recounts the "true" experience of the analysand that we all know is not always accurate as in completely rational and straightforward. Still, the important role of the book is to show Winnicott's approach as a practitioner of his time, a rather daring approach given the tensions between various psychoanalytic schools, with Melanie Klein and Anna Freud being still alive and very opinionated :)