If this classic still painting looks 3-dimensional, it's because this parody really is. What really is classic here is the frame. Dating from the 1800's, it was rescued from an estate sale in rough shape. No one corner was intact. But with a lot of careful molding and plaster work, I was able to restore this beauty to near original condition.
Original condition probably needs some definition. The outer frame is circa 1800's. But it was "updated" probably in the 1940's (give or take a decade) by adding the oval insert. It was then textured over in the middle area to cover the seam between the original square opening and the new oval opening.