This image previously appeared in Terry Bennett's "History of Photography in China: Chinese Photographers 1844-1879", published by Bernard Quaritch in 2013, with the caption:
Fig. 6.43. Pun Lun. Ornately decorated back of a typical cabinet card from
Pun Lun’s Hong Kong studio, c.1890.
See http://gwulo.com/node/31857 for more information.
It is reproduced here with the permission of the author and publisher.