After the Potsdam conference, Germany was divided into four occupied zones: Great Britain in the northwest France in the southwest, the United States in the south and the Soviet Union in the east. Berlin, the capital city situated in Soviet territory was also divided into four occupied zones.
I think it was to show how Mercutio and Benvolio were laughing and slightly mocking the capulets whilst also adding the idea that they always pick the fights and are the antagonists
