A display device for displaying an image and a method by which the display device operates to display an image are provided. The display device may include a display configured to output a screen image, an image sensor configured to acquire an image signal, a bending detection sensor configured to detect a bending motion or a bent state of the display device, and a control unit configured to control the display to display an image, which is generated based on the image signal, in a region according to a position at which the display is bent on the screen image if the bending detection sensor detects the bending motion or a bent state.