Nick's fantastic dream involves El Greco figures. What is the dream, and what might this dream represent in regard to Nick's present feelings about the East?

The people in Nick's "circle" is the story look good on the surface; they are beautiful and wealthy and seem to have everything in life they could need.  Yet, like the stretches with the woman on it - a woman no one cares about - these are people who just go through life without giving any attention to someone who might need it.  These are an example of the way in which the "Roaring 20s" are living a life which is solely focused on oneself and one's own life.