These virtual, exterior door mirrors are much smaller than traditional side mirrors and they will have a camera built into them. An OLED screen is mounted on the interior in the corner between the dash and the door and come with a few different viewing modes.
https://www.carscoops.com/2018/05/audis-fully-electric-e-tron-feature-advanced-aero-worlds-first-virtual-door-mirrors/
https://www.carscoops.com/2018/05/audis-fully-electric-e-tron-feature-advanced-aero-worlds-first-virtual-door-mirrors/