The video recorded the washing process of Expedition 36 astronaut Karen Nyberg on the ISS International Station.
Whether your hair is short or long, in the weightless world, they stand up. And of course the astronauts can't flush the water like they do on Earth, they have to apply shampoo on a towel and swipe along the hair to clean it. Even astronauts can't let their newly-washed hair out of a towel, because suspended hair can stab the eye or be inhaled by astronauts.