A display mirror assembly for a vehicle includes an electrochromic cell, a switchable reflective element, a display module, an ambient light sensor, and a controller. The controller automatically selects a display mode or a mirror mode in response to a detected ambient light level. In a display mode, the controller activates the display module, sets the switchable reflective element to a low reflection mode, and sets the electrochromic cell to a clear state with minimum attenuation. In a mirror mode, the controller deactivates the display module, sets the switchable reflective element to a high reflection mode, and varies attenuation by the electrochromic cell.