In a number of larger cities that have Apple’s in-house map data, a handful of 3D buildings have been touched up by the Apple Maps Team in order to make them more closely resemble the actual structure they represent. Here’s how identify these buildings:

First, enter Dark Mode.

Second, zoom in to a large city (note that this doesn’t work for the DCE cities, like New York and London).

Finally, the light gray buildings are the buildings that have been adjusted. Examples below:

A subset of these gray buildings are buildings that were manually created in their entirety by 3D artists (not just adjusted).