Photos like this have been published in the past, featured in the book, "Lost Tibet". The man depicted holds a bow in his left hand, clearly suggesting he is a part of the Monlam Festival where such men dress up in warrior costume. The round 'mirror' hanging from his neck is the type of thing that 'seers' or the oracles of the state wear. Clearly he is a special person posing for this photograph circa 1900.