The 3D model probably already exists because it was designed in CAD. They probably have custom renderers for rendering the flat/cartoon illustrations for the a

The 3D model probably already exists because it was designed in CAD. They probably have custom renderers for rendering the flat/cartoon illustrations for the assembly instructions, and PBR renders for rendering realistic views. Grab a bunch of of these resources and put them in a box and you have living room design without having to manufacture, assemble, light, and shoot it in the real world.