So this experiment seems to create a virtual atom (the box with the mirrors), yet unlike a real atom, this system isn't quantized internally, so it's possible t

So this experiment seems to create a virtual atom (the box with the mirrors), yet unlike a real atom, this system isn't quantized internally, so it's possible that you could get quanta of any energy up to the sum of all photons inside the box. Alternatively, it could be that the language used by physicists has overloaded too many conventional words, and the impedance mismatch between them and the public can not be overcome.