I agree with Mostel - for Tag Heuer and its target market this sort of concept watch adds interest to its regular offerings. And whether the innovation is "practical" or not at this stage is irrelevant. There is a trickle down effect of some aspect of concept watches, even just coatings or other techniques, to more mundane watchmaking sometime in the future, especially if done my a manufacturer rather than an atelier. And frankly, if I had the money to spend this grandmother would be inclined to purchase something like this (rather than art on the wrist) to encourage technical innovation and have a little bit of the cool factor rub off on her.