This metaphor, of a city as a body, is not new - "comparisons of this kind go far back to Greek antiquity...Plato... compares the human body to a fortified city, and Aristotle, too, uses similar body metaphors" (Feireiss). In the beginning of the 19th century, British city planner John Nash designed a park at the request of royalty and kept the “concept of the city as an organic whole in mind” (Feireiss). The park that he designed was described to “[function] as the city’s lungs.” The impact of similar projects in Paris were described by French city planner Bruno Fortier — “people wandering through the cities’ street-arteries should circulate around these enclosed parks and breathe their fresh air—just as blood is revitalized by the oxygen from the lungs” (Feireiss). 

The gusts of air from the subway, the city's breath, ties the city into the life of the sculptures. Sentimentality in the observer lends it to feel as if his or her life is connected to the sculpture itself. He or she rides the subway, lives in the city, and relies on the city for fuel, for its necessities to live, to be animate.

The city exhales and the animals rise, animated, but are they alive? The subway vents excrete the air, the life force that is pumped throughout the body of the temporary being. The movement is fluid and random, much like a living being. This is one reason humans stop in their tracks when they encounter the inflatable animal in the street.

The air source for the sculptures is hidden, yet at the same time, everyone knows the source. The subway is not a secret, and it is exactly this understood understanding of how deeply the subway twists turns and connects the far-reaching places in the city that makes the breath like that of a human (derived from a body system) in the eyes of the observer. Even if the observer is not a resident of New York City, they can sympathize with the machinery’s intrinsic interdependent web that makes the city what it is. The city is an interconnected body of machines.