Subject: [Update: Not a lance coporal at all. The strip signifies good conduct - see comments below.]
Lance corporal. I believe he's a lance corporal from the single stripe on his sleeve, but please correct me if I'm wrong. I can't sport any other identifying items to help work out who he was.
Photographer: Wing Chong
Format: carte de visite
Date: c.1885. The back of the card gives the photographer's address as "No. 74, Queen's Road, Upstairs. Opposite the Central Market." Wing Chong was there in 1885 (see https://gwulo.com/node/31857)
Photo courtesy of The Pottinger Hong Kong hotel.