Cute, mysterious, and tells a story.
Four cards are displayed. One of them is the blank canvas card.
That card is placed face down on the table. Each of the other three cards has a different colored paint tube on it.
Through the magicians power, the next time the cards are shown the tubes are shorter: Some of the paint has been used!
When the blank canvas card is shown again, we see where the paint has gone. It has magically painted a picture on the canvas.
All four cards transform in the performance and are completely examinable afterwards.
This trick uses a very unique principle to make the illusion all the more astonishing.