The painting is by the Belgian surrealist artist Rene Magritte (1898 - 1967) and is typical of his style - taking everyday images and juxtaposing them in his art to challenge people's perceptions of what they expect to see. With Salvador Dali, Magritte is an artist who's work is popular enough to present a thriving trade is posters of his famous works, which adorn large numbers of student houses around the world.
He also painted the one where it's raining Civil Servants with bowler hats and the pipe that says "C'est na pas pipe" (or whatever) the point being it's a picture.