I'm guessing this is a sibling portrait from the 1890s. With no identifying information on the photograph, other than the photographer's imprint on the front, there is slim hope of discovering who they are. I found next to nothing about this photographer online, which might indicate that J. H. Langhans wasn't in the photography business very long. I was able to locate two Julius Langhans, in the 1892 NY State census, living in Cattaraugus County, but both were listed as farmers. This doesn't mean either man wasn't a photographer prior to this point, but it just doesn't help us identify one over the other as being the subject of our search. Another Julius Langhans appears in the federal censuses after 1900 in Little Valley, but he was born too late to be a match.
Do you have information about J. H. Langhans from Little Valley? If so, please add your comments below. And if, by some miracle, you know who these mystery siblings are, we'd love to hear your story.