Top-right selects the driver's side mirror to use the 'joystick' buttons for positioning, top-left button selects the passenger. With that mirror selected and reverse engaged the positioning buttons determine where the mirror dips to when reversing. Selecting the drivers mirror disables that dipping. Central button folds both mirrors in (and out) for narrow gaps:

No indication of heating on the controls or the mirror glass itself in the form of a symbol. Automatic when the rear screen heater is turned on ... but only the driver's! And that takes a long time to start clearing droplets so has to be cleared manually. may be better with frost. Also driver's side only is auto dimming, you can see a border round the edge of the glass:

The vertical dashed line indicates the wide-angle view from the outer part. The change is gradual not sudden so does it's job of showing what is further off to each side without a sudden change in the image.