alt Hacker NewsI had a similar thought before realizing that I'm pretty sure what they were demonstrating wasn't art style, but adherence to correct physical dimensions and construction of the buildings referenced, that was then expressed in an art style (or reasonable facsimile thereof). The before prompts would just conjure a random building out of thin air, the after prompts searched the web for reference material and then used that in image generation.
And actually, the link I saw a bit ago was this [0] which is more in-depth and has a lot more examples + prompts.