I'll repeat that when I was a Costco member in 2002, the photo lab was moved to next to the front door. With no walls around it. With the front door not having any doors, just a "air curtain" wall going out to the parking lot, which was coated with sand and salt from a New England winter. People were tracking that filth in on their shoes as well.
It was obvious that the results would be disastrous in terms of dirt, I never wasted any money to see how bad it would be.
So, it depends on who's in charge of the store, who runs the machines, etc.