Why is the Save Icon a Vending Machine?

When I saw this comment on a random Facebook thread, I felt my age:

I mean, I understand that we tend to identify images with what's familiar, so seeing the save icon as a vending machine at least makes sense in the "that thing looks like another thing" way.

But what, I wonder, does the vending machine have to do with preserving a document or image so it can be used later? I just don't know.

I know for me, floppy discs are a ubiquitous part of my computer-related experience, from the AOL 3 1/2 inch floppied I'd salvage from the mail and use (can't imagine doing that now with viruses and such) to the massive 8-inch floppies I used on typesetting computers I used in high school, viz:

I've used all three of these; owned computers that used the mid- and smallest variety. And I remember the day I filled a 3 1/2 inch floppy COMPLETELY FULL with data. No one in the world had ever done that before, I imagined.

Also: It really bugs me that the 3 1/2 inch floppy shown here is oriented upside down in relationto the other floppies displayed. But the younger generation, looking at this photo, will likely not notice the discrepancy because they've never used these things and the youngest don't even know what they are.

It's best to remember young folk, that we Gen Xers grew up with technology. Because of that, we have the ability to both adapt to new technology like you young folks and to complain about it like Boomers. That is our unique niche.