(15 minutes or less)
Cut two pieces of posterboard to the size of the pictures you cut out. If you are using a magazine cover, you can use the whole cover or you can trim off the title. It is not necessary to trim the picture to the outline of the person.
Glue the first picture to a piece of posterboard.
Cut the eyes and mouth from the second picture. Turn them upside down and glue them over the eyes and mouth of the third picture. Glue this picture to a piece of posterboard.
(5 minutes or more)
Place both pictures upside down before letting anyone view them. Then have the viewers look at the two upside-down pictures. Finally, have the viewers look at both pictures rightside up.
Your viewers may or may not recognize the personality in your picture when the picture is upside down. The two upside-down views may look strange (one perhaps stranger than the other); but turn them right-side up and one looks normal, while the other may look grotesque.
Since an upside-down face is not a familiar point of view, your viewers may not have noticed that one of the pictures has been altered. It's only when the photos are turned right-side up, and the view is more familiar, that you notice the real difference.
Make 35 mm slides of the faces of familiar personalities from magazines and newspapers, as well as live photos of friends. Show the slides upside down and have people try to identify them. Then show the slides right-side up. Interesting!