content: "mnt" is used for manually working with removable media, where it would be typed in with the least number of letters. "media" was latter picked by the program udev, to automagically placed removable media. Of course "/mnt/usb" is not much that much easier than typing  "/media/uuid-{1fee6c56-9eee-4bb6-a616-6e788fb12660}". i rather just use "mnt", but the default automagical is on just about every distro.