The commentary to the text will constitute a brief analysis. Before starting to draft it, decide what criteria do you evaluate the text. This will depend on the further line of reasoning.
It is possible to consider separately the content of the text. That is, to pay attention to a topic or problem that it addressed. You have two ways to structure thoughts: to respond to one question of the plurality or to consider all the themes that you found in the text. At the beginning of the review specify, how you understand the topic/issue to make it clear what you're talking about. Then list the most important aspects of the problem and indicate the pros and cons of the author's method of disclosure. Tell me what you disagree and provide arguments in favor of his thesis.
The next version of the comment is the rating of the text from the point of view of its form. It is used in cases when the form is really unusual or claims the title itself. Such a review requires the author's deep knowledge on the subject, since it will be necessary not only to give their assessment, but also to justify it: to quote authoritative sources and to compare the text with examples from history and the present.
A deeper analysis can be obtained with a matching of form and content. In this case, write in the comment what problems, in your opinion, decides the text and what techniques from the point of view of the form used to create it. As far as they are sufficient and appropriate for its meaning that you read.
The figure of the author in the text can also become the object of attention. Tell us how the real author (ie, a live person with a specific biography) relates to the narrator in the text, how are their viewpoints and the consequences of such interaction. In the comments of this kind it is important not to get personal, to perceive the person who wrote the text, and his alter-ego in the work by some distance.
Finally, you can perceive the text as a fragment of reality. Comment on its relevance in a specific social and political conditions, compare with other works on similar topics. Analyze the contribution made by the author in the disclosure of the question compared to the whole history of its study. When writing a review of this type ensure that each of your conclusions were confirmed by sufficient number of arguments.