In the 1890s, James B. Shaw of Atlantic City, New Jersey, developed a technique for taking one picture of a person and getting an image that showed that person from five angles. These came to be known as photo multigraphs. Since these five images were usually all facing each other, the effect was that of a group having a conversation. The secret behind these photo-multigraphs was simple: the subject was set in front of two mirrors set at a 75° angle.
The novelty of this setup lent itself to photo booths set up to take pictures of tourists at seaside resorts and amusement parks. The fact that it was developed in Atlantic City probably also had something to do with that. People could pay a dollar or two and have several copies of postcards made of themselves to send to friends back home. Photo-multigraphs were popular for decades, but faded in the 1950s when more tourists began carrying their own cameras. But it's not completely gone. In 2018, Iain Forsyth & Jane Pollard used the technique in an art project. See a gallery of a couple of dozen whimsical photo-multigraphs at Gods and Foolish Grandeur. -via Messy Nessy Chic