Criticism
Art, like nature, has to be distinguished from the systematic study of it, which is criticism. It is therefore impossible to "learn literature": one learns about it in a certain way, but what one learns, transitively, is the criticism of literature. Similarly, the difficulty often felt in "teaching literature" arises from the fact that it cannot be done: the criticism of literature is all that can be directly taught. Literature is not a subject of study, but an object of study...
--Northrop Frye, The Anatomy of Criticism: A Polemical Introduction
Book reviews in an age of social media are primarily a kind of marketing. What happens here is something different: an attempt to understand the breadth and depth of the stories that can be told.