The laugh from a person who didn't get the joke until everyone else in the room had already finished laughing at it.
Jokester: "He stayed up all night wondering if there was actually a dog!"
Persons 1 - 4: "HA HA HA!"
Person 5: forty-five seconds later
"Oh! Instead of a GOD! What a great joke! HA HA HA!"
Jokester: "Nice afterlaugh. Next time, try to keep up."