I think the images are independent of one another.
Each type of image stays in the same position on the screen.
In other words, the 2d part acts just like 2d if it was only on one screen but it takes up the left half of the screen. It will stay at the left half of the screen until you change the view. As far as scrolling, newer information is always at the right and older information gets scrolled to the left.
I hope this helps.