contrast: a big contrast I noted in this passage was the on about good vs. evil that has been a common theme throughout the book. It is clear in the book that the man's job is to keep the son alive, if he fails at that there is no reason for him to live demonstrated by the dad washing brains out if the son's hair. but for other people they may have a different reason to live and therefore are willing to be bad as long as it doesn't violate there reason to live.
parallel: I think a common theme is the boy looking to the man for advice and reassurance. the boy asks of the man many questions like on page 77 when the boy asks if they are still the good guys and the man answers yes they are. on page 83 the boy again asks if they are going to be okay and the man replies yes they are because they carry the fire. the boy doesn't realize yet but the man will not be there forever and the man is gradually teaching the boy to survive on his own.
questions: why does the boy care so much about the dog when they live in a world where everything is dead or dying? is it because he is trying to hold on to whatever humanity the boy and the man have left?