Say you worked in a photo processing chain, let's call it Crack's, where, like so many other commercial businesses, the onus is more and more on the customer to provide their own service. Much like grocery store chains that now have self-serve checkout counters, your photo processing chain has installed a self-serve photo finishing kiosk, to which customers are directed, so that they can customise their own photos.
So when a customer brings in their nerd stick, you take them over to the kiosk and you show them how to start it and then you leave them to it. Right?
But what happens when that customer returns the next day with the slip that the kiosk has given them, containing their transaction number, to pick up the photos they assume are now printed? Is that the proper time to inform them that the slip of paper the kiosk spat out at them after it finished is what the customer should have then given you yesterday, so that you could enter the order into the system?
And when you are telling them that, sorry their files no longer exist in the machine, what do you expect them to say when you lean over and tell them consolingly "you're certainly not the only person that this has happened to"?
Although it is good of you to assure them, when they suggest that well then perhaps someone should post a notice on the kiosk informing customers of this fluke, that by golly, you are going to do that! That makes everyone feel so much better that Baba is not going to get her photos for at least another few days.