I skipped over the gels section, because it wasn’t that interesting. But I do think this was noteworthy for his use of the materials’ reflectivity.
He lights the back wall, and aims it so that when it bounces from the wall and hits the granite tile, there’s that softer gradient look. And this is a much more subtle effect than aiming the light at the tile. It also adds to the photo because of the light to dark contrast from one side to the other.