This is a well known picture of Spotted Tail, printed before in many books as a portrait by Henry Ulke, who had a photography studio in Washington with his brother Julius.
However, as we can see from the identical clothing and scarf of Spotted Tail, the picture is one of the few single portraits of the 1877 delegation which has surfaced to this date.
(cropped from the delegation photo of 1877)
Henry Ulke did paint a portrait from the photograph, but did he take the photograph originally? The inscription on the photograph was clearly written by Charles Milton Bell. or did he just copy the original from Ulke?
its interesting that the photographer has suggested a certain type of look and pose to Touch the Clouds that very much suggests the way that a white man of this period might have compose himself for a photograph.
In fact looking back of a number of photos of warriors in particular, one sees them striking similar poses, which makes one wonder if they are also following instructions. Of course just like white people, they were forced to adopt these types of poses due to the time it took to take an image, but one wonders how they would have stood, and posed had the process been a lot quicker.