The shoe fitting fluoroscope was a common device used in shoe stores from 1930 through the 1950s.
Basically, it was a wooden box with an open x-ray tube and no reliable shielding to protect bystanders. You may want to think of it as an X-Ray Bomb, everyone near the machine was getting a full dose of radiation for 5 to 45 seconds at a time.
It was first used on soldiers in the military to speed up the processing of large numbers of injured personnel.
Many shoe salespersons put their hands into the x-ray beam to squeeze the shoe during the fitting.