Since a display device is used in a relatively large room, it often displays images on a large screen. On the other hand, a display terminal often displays images on a small screen. Therefore, when the same image is displayed on the display device and the display terminal, the displayed image on the display terminal is so small that the viewer has difficulty in discerning details of the image, which poses a problem that the display terminal is disadvantageous. In a display system including a display terminal and a display device, the display device detects position coordinates optically pointed out by a pointer on a displayed image, and displays a given pointer mark at the detected position coordinates. The display terminal displays a magnified version of the displayed image approximately around received position coordinates serving as a center thereof, and displays a given pointer mark at the position coordinates.