In the video, a person is seen holding three different smartphones in their hands. The person is comparing the size of the phones by placing them side by side. The phones are of different sizes, with the smallest one being the most compact. The person then proceeds to demonstrate the functionality of each phone by turning them on and showing the home screen. The phones have different wallpapers and icons, indicating that they are of different brands and models. The person then proceeds to swipe through the screens, showing the responsiveness and speed of each phone. The video provides a clear comparison of the size, design, and performance of the three smartphones.