The rendered Skewed Cone 3D Mirror produces extreme distortions.  The original image is greatly contracted near the center, dramatically expands up to a certain radius, then the image inverts and begins contracting again.  As usual, the Shifting Effects feature can be used to reposition the result as desired with the mouse, essentially re-rendering the same effect based on different relative positions within the source image.  When this image was saved, a Recreate Script was also automatically saved, so this picture could easily be recreated with the Scripting feature.
Skewed Cone 3D Mirror Rendered