NEW YORK — First lady Michelle Obama is fashion's star, but that's not why she's one of Glamour's December cover models.

Mrs. Obama's work in mentoring earned her the spot, which will be rotated with four other covers. She'll receive a special recognition in the annual Women of the Year issue that goes on newsstands Nov. 10.

In an interview with new Glamour columnist and CBS anchor Katie Couric, Mrs. Obama said being a role model is one of the most potentially powerful things she can do at the White House.

"I see how little bits of exposure and big bits of exposure really change my girls significantly, and I want that for more girls around the country and the world," she said.

When it comes to her relationship with President Barack Obama, he helps her feel "whole," she said. "Cute's good. But cute only lasts for so long, and then it's, Who are you as a person? Don't look at the bankbook or the title," she said. "Look at the heart. Look at the soul."

Mrs. Obama does know people are always looking at her, though, especially her fashion choices. "I can't be surprised that people are interested. But I've tried to be at peace with the choices that I make first, and then be open to everyone else's reflection," she said.

On the Glamour cover she's in her own drop-waist, red cocktail dress with a modified ballskirt and a chunky, bow-inspired necklace. The outfit was from her own closet, and no designer will be credited in the magazine.