I believe the way it works is the warehouse worker is given a number/barcode which they scan, which tells them where the item is. As the barcode has been reused by accident, the worker is pointed towards the box of granola which has the same barcode as the box of boxes!
My further dystopian riff is that the reason for the scan-bar reuse is:
They have a robot cycling around the warehouse, automatically indexing the items for sale by scanning all codes in sight, uploading to a database...that is used by other automated pickers.
On average, you still make a profit even if the wrong thing happens sometimes.
The fact it's a box of boxes is a mcguffin I think.
It could be a box of widgets and what happens is exactly the same.
Except a box of boxes goes to the box department, hence why they reuse it, for everyone else it's easier to throw it out the box.
In fact I don't think a box holding boxes is the same size, so it's a new sized box. Probably why they keep it.
Side interest: You would think scanner would see two bar codes and error. But there must be something slow in scanning per side so you quit after it's found. But I thought the tech would scan every side at once for speed.
So the Granola company buys boxes, puts in the product, sends it back to Amazon, then Amazon accidentally puts it into the boxes pile?
Except wouldn't it be a boxes of boxes pile?
Is the Granola company recycling the outer box?