Areas highlighted on the map in red showcase the highest number of venues that serve a particular drink, and as the New York map above illustrates, Bud Light is by far the most prevalent beer across New York City.
Better to have that piece of work done locally by all the endpoints and have them send a light information stream to the center: a single map coordinate rather than a bunch of tower coordinates and distance measurements.
But it is possible to detect minute deviations in this signal, and these fluctuations - seen as mottling in the map - are understood to reflect the differences in the density of matter when the light parted company and set out on its journey all those years ago.