A digital signage system comprising: a first display device (610, 710, 810, 910); a second display device (620, 720, 820, 920) arranged to be at a first spatial distance from the first display device (610, 710, 810, 910) and having a display screen that at least partially overlaps a display screen on the first display device (610, 710, 810, 910); a third display device arranged to be at a second spatial distance from the second display device (620, 720, 820, 920) and having a display screen that at least partially overlaps the display screen on the second display device (620, 720, 820, 920), and a controller (230, 380) configured to: control the first display device (610, 710, 810, 910) to display single image data during a first time interval, and control the second display device (620, 720, 820, 920) to display the single image data during a second time interval based on the first spatial interval between the first display device (610, 710, 810, 910) and the second display device (620, 720, 820, 920), control the third display device (730, 830) to display the single image data during a third time interval based on the second spatial interval between the second display device (620, 720, 820, 920) and the third display device (730, 830); differently control a brightness of the first display device (610, 710, 810, 910), the second display device (620, 720, 820, 920), and the third display device(730, 830), via lamp units (575, 930), wherein each of the first display device (610, 710, 810, 910), the second display device (620, 720, 820, 920) and the third display device (730, 830) include a lamp unit (575, 930); control the brightness of the display device (610, 710, 810, 910; 620, 720, 820, 920; 730, 830) that is currently displaying the single image to be brighter than the brightness of the other display devices (610, 710, 810, 910; 620, 720, 820, 920; 730, 830) that are currently not displaying the single image, wherein at least one of the first display device (610, 710, 810, 910), the second display device (620, 720, 820, 920), and the third display device (730, 830) is a transparent display. a first display device (610, 710, 810, 910); a second display device (620, 720, 820, 920) arranged to be at a first spatial distance from the first display device (610, 710, 810, 910) and having a display screen that at least partially overlaps a display screen on the first display device (610, 710, 810, 910); a third display device arranged to be at a second spatial distance from the second display device (620, 720, 820, 920) and having a display screen that at least partially overlaps the display screen on the second display device (620, 720, 820, 920), and a controller (230, 380) configured to: control the first display device (610, 710, 810, 910) to display single image data during a first time interval, and control the second display device (620, 720, 820, 920) to display the single image data during a second time interval based on the first spatial interval between the first display device (610, 710, 810, 910) and the second display device (620, 720, 820, 920), control the first display device (610, 710, 810, 910) to display single image data during a first time interval, and control the second display device (620, 720, 820, 920) to display the single image data during a second time interval based on the first spatial interval between the first display device (610, 710, 810, 910) and the second display device (620, 720, 820, 920), control the third display device (730, 830) to display the single image data during a third time interval based on the second spatial interval between the second display device (620, 720, 820, 920) and the third display device (730, 830); differently control a brightness of the first display device (610, 710, 810, 910), the second display device (620, 720, 820, 920), and the third display device(730, 830), via lamp units (575, 930), wherein each of the first display device (610, 710, 810, 910), the second display device (620, 720, 820, 920) and the third display device (730, 830) include a lamp unit (575, 930); control the brightness of the display device (610, 710, 810, 910; 620, 720, 820, 920; 730, 830) that is currently displaying the single image to be brighter than the brightness of the other display devices (610, 710, 810, 910; 620, 720, 820, 920; 730, 830) that are currently not displaying the single image, wherein at least one of the first display device (610, 710, 810, 910), the second display device (620, 720, 820, 920), and the third display device (730, 830) is a transparent display.