Where does the system get the name for a USB file system?

I'm not sure where to post this, so I'll try here. Feel free to have some fun with it.

If I plug in a USB drive, the KDE device notifier tells me about it. It typically gives some sort of name.

I'm wondering where that name comes from.

Here's a case in point that has me curious:

I have an external 80G drive. It's actually on old IDE drive in an enclosure.

So I plugged it in, and the device notifier told me: "Linux Mint 17 KDE 64-bit" (but without the quotes).

I proceeded to click the option for mounting the first partition available. And here you see that as:
What's weird about this, is that the drive actually contains an install of opensuse factory snapshot 20140728. That was a test install to see if I ran into problem. So why is it saying "Linux Mint"?

Okay, I did at one time copy the Mint installation iso to the drive. But, since then, I have twice installed opensuse factory snapshots (root as "/dev/sdf1", swap as "/dev/sdf2" and home as "/dev/sdf3", filling the entire disk between them).

I ran:
which gave an empty string as output. So the file system does not appear to have a label. The same happens with "/dev/sdf3" (i.e. no label). I'm not sure about labels for a swap partition.

None of this really matters for anything. It just seems weird.