it is a 'mona lisa ' smile , but it is nevertheless a smile , and strikes a bizarre note since it is wholly out of keeping with nineteenth-century photographic conventions five tintypes of juhen in our possession show the same subtle little smile and smiles in tintypes of this era are completely unknown it is as if juhen found 'picture taking ' amusing photographs taken near the end of julien 's life , in the twentieth century , also show a smile , but it is broader and more generous it is worth noting that in these later pictures he appears extremely good-natured , and quite simply happy .