[aidenn0]

Yes, the walls and ceiling conducting are important to this (otherwise there would be a large induced electric field outside the room).

There are capacitive elements in the pole which is important for allowing it to be resonant at a wavelength much larger than the room (the wavelength used is over 200 meters).

The very long wavelength means that, in theory, one cuold design a room with less of the perimeter conductive (a wire mesh would certainly work; they suggest that doors and windows, or even conductive panels that are connected could work).