Linux Mint is an ISO image that is meant to be booted, not "played". I assume that is what you wish to do? Boot into Linux Mint? If so, place the DVD/CD in your drive and reboot the computer, ensuring that in your BIOS setup you have the first boot device set to the correct drive.
On the other hand if you do wish to look at the files on an image DVD/CD then you can do this (as root in a terminal):
#mount -o loop /dev/dvd /mnt/tmp
Then navigate to /mnt/tmp with a file file manager.