What significance does the unnamed narrator find in the shapes of airports?

The unnamed narrator gives several examples when she claims that the world's airports resemble objects involving signs and signals. She states, "Sydney's airport is shaped like a plane, Tokyo's like an “enormous hieroglyphic...perplexing” (178), Chinese airports are like “hexagrams from the I Ching," San Francisco's like “a cross section of the spine," and Frankfurt's is “a computer chip” (178-179).