Two men working on the roof of an apartment building with a nice looking skyline behind them.
Two men working on the roof of an apartment building
Two men working on the roof of an apartment building is less descriptive way of saying that that two men are working on a roof of an apartment building with a nice looking skyline behind them.
There are both men working on the roof of a building.
Two men working on the roof of an apartment building is stated in both sentences