Another 9.1 live CD oddity

What's with the two entries for /dev/root? furbyzilla:/ # df Filesystem 1K-blocks Used Available Use% Mounted on /dev/root 1585916 1585916 0 100% / /dev/root 1585916 1585916 0 100% / tmpfs 258096 0 258096 0% /dev/shm /dev/sda2 635323 348559 253945 58% /mnt