In the video, a person is seen using a cotton swab to create a marble effect on a glass bowl. The bowl contains a mixture of paint in various colors, including red, green, blue, and yellow. The person dips the cotton swab into the paint and then touches it to the surface of the bowl, creating a swirling pattern. The person repeats this process several times, adding more paint to the bowl and creating a more intricate design. The video captures the process in slow motion, allowing viewers to see the details of the marble effect being created.