It’s undeniably clever. What you’re looking at here is an advertisement for Hut Weber, a German milliner. When this ad was published it caused mass controversy in Germany for depicting Adolph Hitler, who remains a taboo topic in the country. But how do we even know Hitler is portrayed here? There’s no mention of him at all in fact.
We know what is represented in this advertisement because of the signs. Signs are representative of real world objects an ideas. This ad uses visual signs but words, symbols and even sounds can be signs, as long as they signify something.
Signs have both denotative and connotative meaning. Denotative is what the image is, connotative is what that images represents. This ad denotes geometric shapes modelling faces – one with a hat on. What it connotes however is two different humans; one a famous entertainer and the other a tyrannical despot. The images don’t even have to show their complete faces to be effective. Through shared knowledge (widely understood information) the viewer can understand the meaning. The use of the hat clearly identifies the right image as Charlie Chaplin. The small altercation entirely changes the viewer’s perception.
The “Hitler” face is denoted by a side-parted hairstyle and toothbrush moustache. These can be called signifiers, an image (or word etc.) which evokes the idea of something else. What is evoked is called the signified, in this case Hitler. The signifiers evoke further concepts however. Hitler’s image suggests ideas such as war, murder, genocide. This suggestion explains why the advertisement created controversy.
The other signifier in the image is the hat, which changes the signified from Hitler to Chaplin, emphasising the advertisement’s text “It’s the hat”. It really is. The application of shared knowledge (eg. Charlie Chaplin is widely recognised by his bowler and toothbrush moustache) alters the audience perception and forms the advertisement’s message – Our hats make all the difference.