A method provides additional information from a server to a visible light communication terminal through visible light communication in an information display device having a Light Emitting Diode (LED) backlight unit. To this end, if content data regarding an image output through a screen of an information display device is provided from a server, it is determined whether additional information regarding an object of the image is included in the content data, and if so, the additional information is acquired from the content data. The information display device controls light emission of an LED backlight unit of a display unit based on the additional information, thus performing visible light communication. As such, various additional information regarding an object of an image displayed at a particular position of a current screen of the information display device can be provided to a visible light communication terminal.