Symbolism, Imagery, Allegory
In Nector Kashpaw's experience, a good portion of non-Native Americans seemed to be fascinated with images of dead and dying Native Americans—and he wanted no part in contributing to such representations. However, unfortunately, he ended up doing so regardless of his scorn for "dead Indians."
But let's back up a little bit and start at the beginning. Nector first put his finger on the American fascination with dead Indians when he was cast in a movie in the most "important" Native American part… which simply involved him dying. No dialogue or significant screen time—just falling off a horse dead. That doesn't sound terribly important to us.
As Nector puts it, "Death was the extent of Indian acting in the movie theater" (7.1.4). Since Nector wasn't down with that (gee, we wonder why?), he passed on the role, saying that dying once in the course of a lifetime would be quite enough for him, thankyouverymuch.
Then, later, a woman offered him a ton of money to paint him. He was super skeptical at first, and he firmly refused to do the job in the nude, but he did ultimately end up posing while wearing a diaper—not while doing anything, but just standing there.
Unfortunately, much to Nector's surprise and dismay, the painter then ended up representing him as jumping to his death:
I could not believe it, later, when she showed me the picture. Plunge of the Brave, was the title of it. Later on, that picture would become famous. It would hang in the Bismarck state capitol. There I was, jumping off a cliff, naked of course, down into a rocky river. Certain death. Remember Custer's saying? "The only good Indian is a dead Indian?" Well, from my dealings with whites I would add to that quote: "The only interesting Indian is dead, or dying by falling backwards off a horse." (7.1.15)
So, yeah, in Nector's experience at least, white men seemed totally disinterested in representing actual Native American lives or voices, instead portraying them as silent and/or dying. And Nector, through that painting, came to embody that representation, despite his best efforts.