You are overlooking Buenos Aires or the White City, as I call it. From atop the roofs you get the impression that the city has been covered with white powder. Wherever you turn, from afar the whole city seems white-washed and pristine. The barrios you are looking at are Monserrat and San Telmo. Almost every building, every structure, every surface, even the sidewalks appear white.
There are more bird's eye views on Buenos Aires Perception:
Buenos Aires Concrete
Mind Blowing View Over Buenos Aires