The varied architecture of the buildings of New York is fascinating, to say the least. Nonetheless, one salient quality of several buildings such as the UN Building, the Seagram Building, and the Lever House are the tinted glass of green, blue, and brown that cover at least one wall. So, these skyscrapers seem like giant votive candles to the altars of commerce and power. Votive candles are contained in tinted glass containers; the candles are lighted as intentions for prayer on behalf of the needs of a person. These candles are lined up before an altar where there is often a statue or picture of a figure connected with the religion to which the votives are associated.
With respect to the Seagram's Building which has a curtain of "whisky-brown" glass:
The building was, notably, the first with floor-to-ceiling windows, making the wall a true curtain of glass....
Here, another idea is also the disguise of these buildings that can be used metaphorically as they appear to be mirroring the other buildings, cars, and people near them, reflecting the hustle, the avarice, the cupidity of a commercial world.
One good metaphor would be comparing the towering skyscrapers and their respective streets to canyons. It has been said that the streets of Manhattan are examples of man-made canyons instead of natural canyons; the "water" of cars and pedestrian traffic moves along the "riverbed" of asphalt, while windows and flags form the texture and topography of the canyon walls. Looking down a Manhattan street from a window view, one can see far into the distance, and yet barely at all to either side; sometimes, the sky is concealed by buildings (rock walls) so high they seem to curve over. Construction creates new cityscapes and changes the appearance of the rectangular canyons, just as a river slowly carves new walls into the sediment and bedrock beneath.
Describing New York City from a plane: I peered down upon the grey intertwined ropes that carved through the endless rows of skyscrapers.
New York's buildings are Jack's metal beanstalk's to endless clouds.