This looks like a fluoroscope, basically an X-ray that is constantly turned on. The tech is looking at a live X-ray view, not a film transparency.
The radiologic exposure for both of them is orders of magnitude higher than a normal x-ray that we think about. A normal xray exposes you for less than a second, this is bombarding him with X-rays the entire time he is standing there.
Plus he had to do this every day at the end of his shift. Between that and the rock dust exposure I’d hate to see the cancer rates for those guys