As other's have probably said, if they're just working on theory i.e. never had a working prototype, they won't have a demo model until 24hrs before they're going to ship some
if, which is what they should have done, is run a prototype model of one
of course they should do this and then have much testing etc. before mass producing so maybe up to a week minimum before shipping a batch they should have a working product; why not show it off?
Perhaps because, as I mentioned above, it would show nothing. It would, in fact, be mainly a waste of time and Avalon may not have a compelling interest in impressing the segment of the community who would be be impressed by such a feat.
Again though, it would not be big effort or waste much time, so why not? An ominous reason could be that it would be admissible, incontrovertible, and documented evidence that they were running a scam if that happens to be the case.