Another portrait of the young Nasir al-Din Shah painted on copper by Bahram Kirmanshahi is in the Musée du Louvre, MAO 776. During the 1850s-1870s he was depicted in a variety of settings, enthroned, on horseback and against landscapes, as here.
Diba, L.S.: Royal Persian Paintings, The Qajar Epoch, 1785-1925, New York, 1999, no.75, pp. 244-5.