You step up this wooden box and put your feet in the slot.
Whichever Mr. Stanley was waiting on your would look into those goggle things on the top and ascertain all manner of amazing things about your feet. Then you got measured. Then you tried on various shoes to pick which ones were THE shoes for you.
It was that x-ray machine that determined I needed corrective shoes. My mom took me to a foot doctor who decided that my flat feet required me to wear brown tie oxfords when everyone else in the whole world got to wear cute mary janes or even keds. I had to wear the uglies shoes on the planet.
I whined and carried on ever year until finally my mother gave up on whatever foot problems Mr. Stanleys' machine had discovered and I got to join the cute shoe club. But by that time I was about 10 and four years of shoe torture had done their job on my psyche.
So yeah, exposure to those machines was really harmful!