A book review is not a “book report.” A report is a statement or announcement. By definition, statements do not show through description and examples. They tell. And, frankly, nobody likes to be told anything very much. (Did you like that last sentence? Probably not. Why? Because I was telling you something.)
But we do like to be shown how things work using description and examples. So, how does the book you have chosen to review “work”? What does the author do to construct the book’s meaning? Why should a prospective reader even spend time reading the book you are reviewing? You have to show the potential reader why they would want to read the book — or not!
To review means something rather different than report. Review means to “look at or over again.” And, if you look at the first definitions that appear at the link at the beginning of this paragraph, you can see that a review is a more interesting thing, I think, than a report as you are meant to provide a “critical evaluation.”
Criticism is an art. And it is closely aligned with scholarly writing, particularly the type of writing we are meant to be teaching you at the University.
Reading critical reviews is a crucial practice in educated culture.
Well written or composed critical reviews help a person (a reader, a member of an audience, a listener, a viewer) understand the importance and significance of a work, helping them rationalize whether it is worth their time, whether it will expose them to some new way of looking at something.
Capable, competent reviews help a person understand where a work came from, how a work was composed, and what the work amounts to.
Reviews are not vehicles for engaging in ad hominem expressions of opinion. Reviews, and this is really important, always take the work seriously that is under review. This means taking the author or creator seriously, not discounting what they are trying to create or show, but understanding the origin of the work, the method the work uses, and its significance.