The book covers saying please and thank you, writing thank-you notes for presents, waiting for one's turn, picking up one's own trash, saying "excuse me" when stepping in front of others, not talking in movies, using a handkerchief when sneezing, sharing toys with friends, putting toys away, following rules (in playing tennis?), talking when angry rather than hitting, being a good sport (smiling when lose and not boasting when win), calling ahead before visiting, arriving on time, knocking before opening a door, wiping shoes before going in, shaking hands or kissing when greeting people, washing before eating, chewing with a closed mouth, not talking while chewing, helping clean up, and saying good-bye and thank you after a visit.
By having Emily Elizabeth support all of these behaviors and having taught them to Clifford, the book sets it up as an expectation that every child should do the same. That's a nice way to establish these practices as the norm, independent of a parent's speaking in favor of them.
PDF version added to MIRRORS