Chicago architecture at night Windows

The first thing you notice is the graphic rigidness of this office building in downtown Chicago.
It's a grid that only changes when the corner of the building is reached and perspective makes the windows in the grid taller.

Then as you keep looking another interesting dynamic seen is the different brightness in each individual window, creating various patterns on the grid.

Then looking into each individual window you get small glimpses, shadows of what is going on inside. Not enough to really make much out but enough to allow you to imagine what is going on, or at least toy with the idea.