Show the audience a small picture in a frame. Then put it on the table and cover with newspaper. When you will get again the audience will see a completely different picture. Lift the paper and again put under her picture. Then remove the paper and show the audience... a completely new image.
How to achieve this? Made of cardboard, make a rectangular screen saver. With the two sides of the seal of her paintings. The screen saver should enter freely into the frame to remove the picture.
First you show us a picture inserted in frame saver. Then put it on the table face down, and, when out from under the newspaper, the splash screen is left on the table and show the audience the second picture. Then lift the edge of the newspaper along with the screensaver, and put them under the picture up face. The screen saver will be in the frame of its other side. So the audience will see three completely different pictures. What is not fun for evenings in the school?