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. 6.51. Wo Cheong (Cheung). Two Chinese actors, c.1890. Hand-tinted
gelatin silver print photograph. Author’s Collection.
See http://gwulo.com/node/31857 for more information.
It is reproduced here with the permission of the author and publisher.