In the video, a person is seen using a tool to apply a substance to a corner of a wall. The tool is pressed against the wall, and the substance is spread evenly across the surface. The person's hand is visible in the frame, and they appear to be wearing a glove. The wall is white, and the substance being applied is of a darker color. The tool used is a flat, rectangular object with a handle. The person's movements are deliberate and careful, ensuring that the substance is applied evenly.