The rifle was originally owned by White Man Runs Him, General George A. Custer’s famous Crow scout at the Battle of Little Big Horn (June 25, 1876). Custer’s scout adorned the rifle with cultural symbols and regarded it as sacred, often using it in tribal ceremonies.
https://www.militarytrader.com/militaria-collecting-101/custer-indian-scout-rifle-auction
Looked it up he also was called White Buffalo That Turns Around & Mahr-Itah-Thee-Dah-Ka-Roosh.
https://en.m.wikipedia.org/wiki/White_Man_Runs_Him
His face in that pic seems to be saying “please stop calling me that”