Because each photograph is only a fragment, its moral and emotional weight depends on where it is inserted. A photograph changes according to the context in which it is seen: thus Smith's Minamata photographs will seem different on a contact sheet, in a gallery, in a political demonstration, in a police file, in a photographic magazine, in a book, on a living-room wall. Each o these situations suggest a different use for the photographs but none can secure their meaning.
Susan Sontag (2011). “On Photography”, p.94, Farrar, Straus and Giroux
