Magician acts as an absent minded professor. He displays a sheet of newspaper to the audience both front and back. He then proceeds to make a cone out of it.
Now he picks up an empty transparent glass and places it into the cone. Almost immediately, absent mindedly, he takes the glass out of the cone and places it on the table. He then picks up a glass full of milk and pours the milk into the paper cone. Suddenly, he realizes that the empty glass has not been kept in the cone and that the milk has been directly poured into the cone. To correct the mistake he now picks up the empty glass and places it into the cone.
After a bit of mumbo-jumbo, the magician takes out the glass from inside the cone. The milk poured directly into the cone is now seen contained in the glass! The paper cone is opened and shown empty. Audience is baffled.