Sorry, I don't understand: "Ultimate Hybrid Piano" what Hybrid stands for? Isn't it for the cabinet look only?!
"Hybrid" is just a contemporary marketing word used in so many industries these days. I guess it sounds better than crossbreed, mixture, fusion, etc
In this case hybrid just simply means that it has components of an AP + DP = HP (Hybrid Piano), It certainly separates itself from "digital piano" IMO. I would expect an HP to be superior to a DP from a marketing standpoint.