The analysis of photos has a long tradition. After Charles Darwin published his famous study on the nonverbal signs of emotions in the second half of the 19th century, Antoinette M. Feleky published the first empirical analysis of emotions through photos in 1914. Building on her preliminary work, Robert S. Woodworth presented a hierarchical classification of emotions in 1938, which can be better recognized the further apart they are from each other. A few years earlier, Werner Wolff had released his studies on the asymmetry of facial halves using halved photos, and only a few years later, Norman L. Munn's analysis of the influence of contextual information on the identification of emotions was published. A common feature of these studies is their phenomenological approach: the authors were concerned with the...