There is not much different between Linux Mint 3.1 and Mint 8 or any other later version. But it is worth having screenshots of it since it is the earliest version of Linux Mint still available for download.

The Mint splash screen.

After logging in for the first time you are greeted with an initial setup thing that you won't see anymore.

The Linux Mint 3.1 desktop is the same as later versions

The menus are the same

And so is the file manager. Or at least as far as Mint 11 it was the same. Now of course it is not.