1. An image display system configured to display an image, comprising: an obtaining unit configured to obtain a surrounding image indicating surroundings of a vehicle; a plurality of detectors disposed on the vehicle at different positions and configured to detect an object existing around the vehicle and to detect a distance between each of the detectors and the object, respectively; a specifying unit configured to specify a specific detector which has detected the object from among the plurality of detectors, and to specify a specific distance between the specific detector and the object; an indicator selection unit configured to select an indicator in the form of a frame based on the specific detector and the specific distance; an overlapping unit configured to overlap the indicator with the surrounding image, the indicator indicating the object and the specific detector; and a display configured to display the surrounding image with which the indicator is overlapped.