But their physical resemblance must be a source of perpetual confusion to the gulls that fly overhead. To the wingless a more arresting phenomenon is their dissimilarity in every particular except shape and size.
In this passage, Nick Carraway suggests that in the natural and organic world, there is no difference between East Egg and West Egg. The islands are essentially the same to birds because of their similar “physical resemblance[s]”.
However, in the social world, East Egg and West Egg could not more different. East Eggers, so to speak, come from a line of old wealth and stature, where modesty and class is valued and appreciated. West Eggers, on the other hand, have succeeded and achieved the American Dream, and are relatively new to wealth, upper class society, and learned etiquette.
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