In the video, a person is seen using a piece of plastic to create a watercolor painting. The person places the plastic on top of a white sheet of paper and then applies watercolor paint on the plastic. They then press the plastic onto the paper, creating a colorful design. The person repeats this process several times, adding more paint and pressing the plastic onto the paper to create a layered effect. The final result is a beautiful watercolor painting with a unique texture and color blending.