This is actually a funny joke. Couple of kids fill the trunk with cases and cans of Coke. They try to fool some people on the street. Then they get the attention of the police, and decided to punk the cops.
The officer seem to enjoy the little prank. It was in good hearted fun.
Notice how because the suspects were compliant and respectful the full encounter the officers also kept in a respectful demeanor. No one gave the officers reason to escalate the situation so it never was. In the end they could all laugh and shake hands.