 The front face of each tower is animated with a continuous , dynamic exhibit of lights and electronic images . Although the screens on the towers periodically display clips of landscapes such as waterfalls , most intriguing are the display of faces of Chicago residents . About 1 @,@ 000 faces of <unk> are shown in a random rotation , the order determined using a Barco show controller . Each face is displayed for five minutes , with a brief period between each of these videos during which the sculpture is <unk> . As a result , no more than 12 faces appear per hour during the summer . However , during the winter a version without the final one minute of puckering is shown , so the video segments then are only four minutes each . The video pattern also includes a three @-@ minute water scene every half @-@ hour and a 30 @-@ second fade @-@ to @-@ black every 15 minutes . If all the faces were shown consecutively , instead of randomly , they would each appear about once every eight days . A June 2007 article in the Chicago Sun @-@ Times reported that many of the subjects who had their images <unk> for the project had yet to either see their own images or hear of anyone who had seen them . 
