1. Reserve your square, take a 450 x 450 screenshot as normal.

2. In Photoshop choose Image > Adjustments >Invert to invert the colors of the image.

3.) Choose Image > Image Size and uncheck the "Constrain proportions" box. Change either the width *or* the height to 100 (or some other random but small value). Click Ok.

4.)Choose Image> Rotate Canvas> 180.

5.) Now locate your "square" which should now be inverted, squished and upside-down, and blend the surrounding areas using standard techniques.

6.) When done, reverse steps 4.) then 3.) then 2.) You will now have a "proper" square created in this alternate universe.