You are expected to be sympathetic about someone else's tragedy.
Tom had just told his friend Jeff that his pet dog had died.
Jeff wants to talk to Tom about the dog.
Jeff tells Tom that it is okay to be sad about the loss of a loved one, even if it's a dog.
Jeff tells Tom that he shouldn't be upset because the dog wasn't even a person.
Tom feels better about the passing of his dog and continues talking to Jeff about it.
Tom is even more hurt and avoids talking to Jeff for a week.