The title the photographer gave this shot, "ironing," has me slightly baffled.
My best guess is that the man is stretching long sheets of an unknown material - fabric, perhaps? - by attaching stiff rods to the bottom widthwise that are longer than the fabric is wide. The tension (you can see a finished piece to the left) on the rods will keep the material taut until it is dry or has finished curing.
Japan 1914 - 1918 I own the originals of these unpublished family photos. ... As a salesman for Atkins Saw Company, Elstner Hilton traveled to the Far East to sell commercial sawmills in the early years of the 20th century. ... Elstner Hilton was my father-in-law Frank Hilton's* brother, which makes him my spouse's uncle. ... * Elstner Hilton's brother Frank Hilton compiled a scrapbook of photographs, clippings and other ephemera at Stanford University between 1907 and 1911. ... ps: I now have reason to believe that the photos of Japan may be stock photos that Uncle Elstner purchased and pasted into his album. There may be some exceptions: the images of his sister, Miriam, and photos of logging operations in the Phillippines.