kapoor's piece is titled cloud gate because
It reflects the sky
Cloud Gate
By reflecting the sky, visiting and non-visiting pedestrians and surrounding 
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Cloud Gate [SEP] "Cloud Gate" themes
"Cloud Gate" is described as a transformative, iconic work. It is similar to many of Kapoor's previous works in the themes and issues it addresses. While the sculpture's mirror effects are reminiscent of fun-house fairground mirrors, they also have a more serious intent; they help dematerialize this very large object, making it seem light and almost weightless. "Cloud Gate" is considered Kapoor's most ambitious use of complex mirrored form dynamics. Kapoor challenges his viewers to internalize his work through intellectual and theoretical exercise. By reflecting the sky, visiting and non-visiting pedestrians and surrounding architecture, "Cloud Gate" limits its viewers to partial comprehension at any time.