... a particular 59 seconds of the introductory demo was sheer brilliance. At the Stanford d.school where I teach, I'm all over students like a broken record, repeating a mantra of "show, don't tell. show, don't tell. show, don't tell". A great demo is one where you show how all your hours of process brilliance have created something truly remarkable, but the point of proof lies in only showing that which is remarkable, rather than telling us how you got there. In other words, show, don't tell.
Take a look at the rhetorical brilliance of Steve Jobs in his iPhone 3G introduction here. Forward the video to the 1:27:21 mark, and watch through 1:28:50 to see an awesome 59 seconds of demo magic. Show, don't tell.