The starting Aesthetic is an option when you start a new map. The main issue with it is: all you get is a vague "Style 1" or "Style 2" and little else. Which is frustrating, at least to me, so here's a simple, easy visual of what buildings you can build in each style as well as the version you unlock with research.


Look at it from left to right: the building on the left is what you start with, the one on the right is the most "evolved" version you get via research.

Hope it helps!