In simple terms, cow piss has a bunch of nitrogen in it which makes the grass grow faster (especially when you have a well developed soil biome).
I watched the video and appreciate that quality engineering went into this product, I just don't get why it would make sense for any farmer who has cows in pasture to invest in this technology, even if it were available at mass-produced-in-Asia prices. More specifically, it's hard to imagine a use case for cow piss that makes it valuable enough that I'm going to spend tens or hundreds of thousands of dollars on machinery to harvest it, at an opportunity cost of less nitrogen going into my fields.
Maybe it makes more sense for feedlots? They get a bunch of nasty health issues going on with their animals living in mucky high-density conditions, so reducing the ammonia in the muck might lower the amount of sores their animals have, or something like that. But taking a step back, I guess I don't get the general wisdom of inventing technology that makes bad practices marginally better on the animals and/or environment.