When I was working for Rigid Containers (a U.K. box maker) for a year or so, I worked on platen presses and die cutters/ flexographic machines. You chuck a pile of fibreboard in the back and depending on type it comes out folded / trimmed and printed the other side, some glued, others stapled. This would be about 1975.
The print blocks were just rubber blocks on backing sheets which fixed to the print rollers, and you got a sketch for job set up showing the position on the box where each logo / block of text went. You did a test run, then the supervisor would have a quick look check dims with a tape and each block was on the right panel - and then off you went. I can't recall how many boxes per hour they did, but they ran like express trains as all the jobs were piecework back then.
On more than one occasion I recall hearing about jobs that had ''slipped through'' and been delivered slighty or badly wrong, some were rejected and the staff got a rollicking for letting the job through, but normally the customer needed the boxes and if all the info was on there but just a bit wonkey or on the wrong panel, they sent a message to get it right next time, but they could use the boxes and they perhaps got a discount on the next order to keep their custom.
I suppose if there was a mistake in communication somewhere, and boxes arrived a bit wrong, but they had shipments to fill, they just sent them out if the print was not blurry or obviously bad, none then would have imagined in their wildest dreams that people would be musing on it generations later
ATB, Ed