They are doing the same thing in the C4 video. Your method is just as easy as using the Control4 app and it will work just as well except you have to rely on an RTI driver vs a Control4 "app". RTI might even be better since you are not confined to the functionality of the app.

Someone builds a floor plan in photoshop and imports it into RTI (or any 2way control system UI software). Then you use button tools to create "overlays" for the rooms. When these buttons go high because of motion or water or whatever.. the button changes states and the room "lights up".

We use icons for different things like motion or water etc. The inactive state of the button is transparent and the active state is the icon for motion or an open window or whatever.