In the video, a person is seen holding a clear plastic bag and placing it inside a cardboard box. The box is empty and has a piece of cardboard on the bottom. The person then proceeds to fill the bag with water and seals it. The water inside the bag is visible through the clear plastic. The person then places the bag inside the box and seals the box with tape. The box is then placed in a freezer. The video ends with the person removing the box from the freezer and opening it to reveal the frozen water inside the bag.