I'm with @Dakine on this one. Really useful move to control speed on the steeps and, when done correctly is not a check turn but an unweighting of the back of the ski to bring it around while engaging the tips to initiate the carve. It feels like a continuous weight shift forward and back as the edges engage over the length of the ski. I'm not nearly as smooth and balanced as the skiers in the video but it's a standard tool in the box for me.
Have to say that their poles look about 10cm too long. My wrists ache just looking at it.
Have to say that their poles look about 10cm too long. My wrists ache just looking at it.