That little circular bag tied to their waists is supposed to carry salt, so that the yak herders can give a handful at a time to the yaks. When the herders pat/slap the bag, the critters would come to the herders expecting salt. For information.
Thank you my friends for this beautiful dance and music. It brings much joy to my heart. Some day, if God gives me the time and the money to travel, I will visit your beautiful country. Then I will breath the clean and pure air of beautiful Bhutan. I will see this lovely dance with my own eyes. Until then, may God protect and bless and prosper Bhutan, and keep her free and strong. May He bless her people, and especially her noble king and queen, King Jigme Khesar Namgyel Wangchuck and Queen Jetsun Pema. Long live Bhutan! Long live the land of the mountain dragon! From Australia with love.