Illustrations of 幌子 (huangzi) or store signs that used to hang outside urban shops to advertise and demonstrate what it sold. Unlike other signage that featured text, 幌子 took form as a physical object, displaying the actual products or their replicas. For example, fishmongers would hang wooden fish, wine sellers would hang a wine jug or gourd flask, noodle shops would hang thin strips of paper, and a sock shop would hang a sock. (Probably dates to Qing era)
Sources: Wu Jen-shu and Ling-ling Lien’s chapter (”From Viewing to Reading; The Evolution of Visual Advertising in Late Imperial China”) in Visualising China, 1845-1965: Moving and Still images in Historical Narratives (2012) edited by Christian Henriot and Wen-hsin Yeh, The World of Chinese, 福根儿