...is not good. Looks like you're driving a GT car and your seating position is 50cm above the ground:
That has nothing to do with the position of the truck in the side mirror. Look at the middle display, this cam is on the back of the truck in ~ 70cm high and show exactly the same image.
That position in your game is actually different from what we made. We just tested it here again to make sure it wasn't wrong, but it seems that there is some kind of visual bug on your end with those.
If you had a detailed signature like the most senior people in this forum, we could tell if the problem might be with your AMD card or Nvidia for example...
I do believe there was something with that where the view slightly changes when you turn that on or off. Give that a try and see if that helps to begin with, but we will investigate a bit on our side as well.
I was wrong, it has nothing to do with virtuell mirrors. When i switch them on the truck in the mirrir gets wider, but no changes in high. I also tried to tilt the cockpit cam down, but that changes nothing.