Vergangenheitsbewältigung

Could you say a little more about how to approach this question, or some examples of the kinds of things that make a PhD graduate stand out on the job market? Do you think about this mainly in terms of developing a useful contribution to discussions in the field?

I'm wondering if anyone has ideas about how to choose a book for the book review component of the Yale history PhD application. The website says, "The department requires a short book review (maximum two pages) to accompany the application. It should cover the book that has most shaped the applicant’s understanding of the kind of work he or she would like to do as a historian." Do you think it should be a book that is very close in subject matter to my research interests? Or, maybe a book about a different topic, but which uses similar methods?