There were several men called Whirlwind in Cheyenne history. The man in the Snell photo and in the 1872 photo must be Old Whirlwind (ca.1823-1891), a Southern Cheyenne chief of the Peneteka faction of the Hevhaitaneo (Hair Rope) band, in reservation times situated west of Watonga, Oklahoma on the North Canadian River. (see John H. Moore “The Cheyenne Nation”)

His son was called Young Whirlwind; maybe he wears the war-bonnet in the last photo.

There also was a warrior named Little Whirlwind among the Northern Cheyenne. — Dietmar Schulte-Möhring

Here is the 1872 photo of Whirlwind:

Here's another, a rather impressive looking Whirlwind, obviously not the same Cheyenne?