She had falsely claimed Native American heritage in the past... yes, that "Aryan" claimed to have Navaho genes, and used that claim to further her career.. so they say.
That is why Trump calls her that... to remind people of her past dishonesty and poke fun at the ridiculous old claim.
1st, Warren never claimed to be Navaho. 2nd, she didn't 'further her career' by indicating CHEROKEE blood and 3rd, Pocahontas was neither Navaho nor Cherokee but rather Powhaten.
She can't back the claim, however. And she did use it as a bullet point of sorts for her image. Regardless, what Trump did was entirely messed up.
1) Wasn't the occasion (honoring war veterans)
2) Certainly not the company (Native Americans!)
3) Trump trying to use "They" instead of "I" to make it more "popular"
4) Trump's insistence on attacking people from afar, instead of in person. Trump is a fucking coward.