Blades with fins, it is an interesting idea just don’t take them in the half pipe!
Seriously I see you’ve been mocked on TGR and SHeads but I think the short ski concept is interesting. 15 years ago everyone ridiculed the idea that serious skiers should ski anything shorter than your own height + 10cm. I remember back in the mid 90s I fitted touring bindings to the first carving skis that were appearing at the time - the idea was to reduce length and get more surface area and easier turning off piste. No-one thought it was a good idea to use piste skis “off piste”. The final argument was that the didn’t have the little dinky “rando” hole on the spatula (remember those?).
I’m not convinced by the fins… although the rando guys have used a similar concept of keeping their skins on for descents to slow speed (technique used by beginners where there is limited space to turn). This is a bit like keeping your harscheisen on for the descent. Still the skier in your vid seems to be having fun and is riding much better than in the last video.