The video shows a person's hands demonstrating how to cast on with a thumb. The person is holding a wooden knitting needle and a red yarn. They are wrapping the yarn around the needle and pulling it through to create a loop. The video is shot against a white background, and the person's nails are painted pink. The yarn is bright red, and the wooden needle is light brown. The person's hands are in focus, and the movements are clear and deliberate.