Why should a review begin with an objective summary?

So the audience has a solid background of the material that will be criticized later.

A review is a text that provides an interpretation and critique of another text, or of a collection of texts. Reviews usually begin with an objective summary of the material that is to be discussed. This is done in order for the audience to have a good knowledge of the material that is to be criticized later. Moreover, even when readers are already familiar with the previous material, a summary will give them a quick refresher to ensure the most important points are understood and remembered.

2nd option

explanation:

i'm thinking it would be when compound subjects are joined by or, nor,either-or, neither-nor.