In April 1933, the Nazi government issued a decree that codified the definition of a non-Aryan, associating Aryan identity with biological characteristics. Vishniac’s photograph of his daughter Mara, age seven, standing in front of a store previously owned by a Jew, includes a window display exhibiting pamphlets on Aryan race theory and advertising an instrument used to measure human heads, demonstrating that the Aryan skull is long and thin. The window sign reads “Nurture [your] race!” and advertises an instrument invented by “race researcher” R. Burger-Villingen that measures the cranium facial features to prove one’s Aryan race. A poster in the store window promotes an organization founded in 1933 to disseminate Nazi ideology among the German middle classes and to enforce the boycott of Jewish businesses.