What do you call photography using green boxes?

I know that taking pictures with a green background and then changing it after is called "chromakey" or "green screen" photography.
I want to ask what do you call the ones that people(usually kids) sit on top of green boxes and they later change then to animals(crocs, rhinos and lions) and a bunch of other stuff?
thanks

Is it possible that they are placing the box under the ‘chroma-key’ backdrop?