A vehicular dual-state interior rearview mirror assembly includes a mirror head including an electrochromic mirror reflective element having a transflective mirror reflector. A video display device is disposed rearward of the viewable reflective region and occupies at least 85 percent of the viewable reflective region of the mirror reflective element. With the mirror assembly operating in a first state, the video display device does not display video images and the driver views rearward via reflection at the viewable reflective region and, with the mirror assembly operating in a second state, the video display device displays video images for viewing at the viewable reflective region by the driver. Video images displayed by the display screen at a center zone of the viewable reflective region are at unit magnification, and video images displayed at driver-side and passenger-side zones are not displayed at unit magnification.