It is supposed to be healthier for you to poop that way. I have seen various articles on it and run into those toilets a lot in my work. First time was in Kazakhstan when those were the only type of toilets we had on the crew. Doing your business like that apparently requires a degree of coordination that I don't have and I'll spare you the details beyond that. Suffice to say, I was very happy to get into town, after 2 weeks, and use a set down crapper!
They make an elevated version of the one in the video that seems to work well. Don't try squatting on a regular throne however, they are not designed to take weight concentrated in that manner and have been done to break causing some really nasty injuries to people's backsides.
The washing instead of toilet paper is supposed to be better for you than using TP but I cheated on that part (coordination thing again).
It may be better for you than sitting but I'll take a traditional throne anytime.