How did the upper floors of the Schlesinger and Mayer department store contrast with its lower floors?

The design of the Schlesinger and Mayer department store (later Carson Pirie Scott) in Chicago features a distinct contrast between its lower and upper levels.12

• Lower Floors: The first two floors are characterized by lavish, exuberant decoration. These windows were treated as display areas, with the architectural ornamentation forming rich, intricate picture frames. This cast-iron ornament, which incorporates a combination of geometric and stylized floral forms, represents a high point in Louis Sullivan's achievement as a designer of architectural ornament.1
• Upper Floors: In contrast, the upper floors exhibit an elegant simplicity. These levels feature rectangular "Chicago windows"—each consisting of a large fixed pane flanked by movable sash windows—which emphasize the building's horizontal design and the logic of its steel frame.13