[Views of Cincinnati] Crown of the Queen City
The story goes that Gyo Obata, the architect behind the Great American Tower (the city's tallest building), was inspired to model the building's spire after the tiara of the late Princess Diana. Here it is seen from the top of the Carew Tower.
Obata used the inspiration from Princess Diana's tiara since Cincinnati is the "Queen City." The top of the tower is, in essence, the crown jewel of the city.
Meanwhile, others have compared the top as a homage to the Chrysler Building in NYC.
I think it looks like a birdcage.