Answer
If the object and image are interchanged (size and position), the formulas in the summary are only valid for real image formation (i.e when the image distance is positive).
Work Step by Step
The principle of reversibility implies that light will follow the same path if the direction of its travel is reversed. Because a real image is formed by the light rays actually intersecting, the formulas will hold up. However for virtual images, the light rays only appear to meet at a point but are diverging and therefore never actually meet. So the formulas will not function as intended for virtual images. In the diagram below, either of the arrows could be the object and the diagram would still be correct.
