The two cities portrayed in this famous section of The Iliad are the city of peace and the city of war.
The city of peace is holding festivals and weddings, signs of a strong community. The generations are working together, which also shows community strength. There is art and dancing, and people are working out their differences peacefully, in a court. These show how a city at peace functions.
By contrast, the city of peace is besieged, by two groups of opponents who plan to burn the city down and steal all they can carry. They are spying on the opposing army, and then killing them and disfiguring their dead bodies. There is nothing else happening in the city except violence. There is no art, no love, no law.