The impression 150 North Wacker leaves the view is one of squares. The floors are banded in a series of alternating color rectangles. The major block of the building is framed by decorative brackets riddled with square holes. And the main façade is similarly punctuated with off-color glass in regular square patterns.

But there is more to this building than quadrangles. Follow the side brackets downward and you will notice they slope gently outward toward the bottom. Then notice the main facing sides of the building and the way they bulge outward. It seems as if the decorative side brackets are almost necessary to keep the building from tipping over like one of those toy drinking birds from the 1970’s. This, of course, is an illusion, but it leaves a subliminal impression of tension on the viewer that contradicts the conscious impression of regularity, predictability, and squares.