I have this same photo from my grandmother Hazel's collection. Her father was Swan Nelson, born 12 January 1844. He was from Kristianstad. He emigrated to America and owned a farm in Orrock, Minnesota. He died in Minneapolis in 1931 and according to his death certificate his parents names were Nils and Karna.
These people are possibly his relatives who stayed in Sweden. No names were listed on the photo. The back of the photo mentions a photography medal
From 1886 so the photo must have been from after that time.