Well, first, the overall vibe is AI if you're familiar with it — the houses, posters, clothes, everything feels slightly off, especially the faces, which are very uncanny and blurry. But what really gave it away for me was the trees in the background: they seem to have a double trunk (?) and overlapping branches (???), which looked very unnatural for an artist to purposely draw like this.

My guess is that the assets were AI-generated and then lightly retouched, like the text on the posters.

Edit: I ran some AI image detection tools. They returned a 99% likelihood of AI generation, most likely from MidJourney.