yeah, I've played with it. it is hard to change the way I think about interacting with the infotainment system. the old car didn't have anything like this ability.
it is only supported on screens that show the hand icon in the lower corner, I think that only shows up when you hand is detected near the screen. then you can just flip the screen left or right. what it does depends on user settings and screen you're on. it changes songs in MP3 mode, it changes to next preset tab when on presets. if on the station page, it goes to higher/lower station. etc.