When Miles needed a place to express himself Aaron found him a spot to paint. Aaron explains he got a job in the tunnel once but we later learn it’s the entrance to the Kingpin’s operation.
I want to think Aaron chose that spot so he could look at Miles’ art on his way to work. Aaron of course has to keep his identity secret for his life threatening job so this is his way of putting his nephew’s picture on his desk, so to speak.
just want a Transformers show where the humans they become friends with are millennials and gen z kids with those generations senses of humor and it makes even the Decepticons worried for them