Everyone keeps calling Iris Apfel a “nonagenarian fashion icon” because how many such people can there even be? Well, at least a few, as the documentary Advanced Style made clear last year. But Apfel deserved a film of her own, even if she didn’t think so until meeting director Albert Maysles, who won her over with kindred geriatric joie de vivre. That’s the spirit of Iris, a movie made mostly just by hanging out — in this case with a child of the Depression who grew up understanding that personal style meant more and lasted longer than pretty looks. Wisely alert to clothing as a cultural barometer, Apfel is a grand combination artist, whose mix-and-match approach to dressing herself contains multitudes. “There’s so much sameness,” she says about what she sees other people wearing now. “Everything is homogenized. I hate it. Whatever.” The same could also be said of fashion-themed documentaries these days, but even a milder offering from the late and legendary Maysles — his last, as it turned out — seems constitutionally incapable of being wholly inessential. Although mostly a loose and unchallenging portrait, Iris is of value to the documentary field if only for taking a stand, however casual, against drabness.