Debian, the cool guy distro in 1999. The machine overlords run on Red Hat.
In the low budget parody version, Neo ran Slackware, and the climatic battle was basically about Agent Smith somehow fucking up his libc.so.6 but then Trinity got him a copy of the file on 3.5" floppy from another system. Or something.
/mnt is meant for volumes that you manually mount temporarily. This used to be basically the only way to use removable media back in the day.
/media came to be when the automatic mounting of removable media became a fashionable thing.
And it’s kind of the same to this day. /media is understood to be managed by automounters and /mnt is what you’re supposed to mess with as a user.