Stretch versus expose

Under the game framing options, what is the difference between ‘stretch’ and ‘expose’. They both seem to have the same function. As in, they both seem to maintain the exact same framing, while changing the aspect ratio.

How do I get the game to change the framing along with the aspect? I want the user to be able to freely resize the frame without warping the image.

Well, I think I found out what happened. Since I had viewports enabled, and they mess with the projection matrix, resizing and shifting the aspect didn’t work. So it stretched instead.