The 1672 painting Easel With Still Life of Fruit, by the Flemish painter Cornelius Gijsbrechts, is a sort of apotheosis of trompe-l’œil: The whole thing — not just the still life itself but the easel, all the tools, the other pictures, and the letter — have been painted on a wooden cutout; it’s all an illusion.
The painting at the bottom has no front — only its reverse is visible. Gijsbrechts had played that joke before.