Great video Chris, the sound is easy to hear now you've defined it for me, cheers.Well, apart from that jangling sound generally, I'd say its the octave G string which gives it the 12 string sound, Dermot. That's why Roger McGuinn of the Byrds had Martin knock him up a 7 string just by adding the G octave.
"Its more like a Swiss Army Knife than a guitar" -Roger McGuinn
Thanks
Dermot