I believe it also doesn't make a lot of sense to have a real Geiger tube and have it exposed.

For the sexond, Geigers are binary, they only report detection events, not types. So you don't want it to be triggered on non-X rays like interferences from computers around, and you might also want to be able to occasionally remove surface contaminants from the equipment. Both of these are easily achieved by giving it a durable opaque case which is how everybody do these.

And for the first, I believe a modern photodiode taped over is by itself more sensitive than Geigers, even more so if coupled to a scintillator crystal(salts that glows in x-rays), not to speak of spectrometer based systems that can additionally tell energy levels therefore types and biological damage levels of incoming rays.

The real Geiger tube running on display is cool, but that's strictly it. I believe.