Signalling that he recognises this is not a typical top-level post; signalling that this book is important, countersignalling disapproval of norms to set this post apart.

My reply signals that his attempt failed in at least one case.

It would have been far more useful to see two paragraphs giving an indication as to what makes the book so great. The quote you provide here would have been great. If that were included it would have made it worth a top level post - in the discussion section.