In terms of scientific advancement, finding a way to make water lock into goofy shapes isn’t exactly world-shaking.
It is, on the other hand, incredibly neat. Especially in motion:
https://c.brightcove.com/services/viewer/federated_f9?isVid=1
So how does this “freezing” work? Researchers coated a surface with an extremely water resistant powder. Then, they dripped the water as a specific speed of 1.6 meters per second.
What you’re seeing is the secondary droplet. The water strikes the powder so hard that it coats the droplets, essentially locking them into that shape, even when they land. Essentially, the powder forms a hard, water resistent crust around the droplet, letting it keep its shape.
This is mostly just neat to watch, but it does have some practical use: It’ll allow scientists to study the effects of physics on water droplets with a bit more accuracy, thus improving our understanding of fluid dynamics. Plus, it’s a fun magic trick, and we can always use more of those.