The 68-year-old Vogue editor-in-chief has praised the reality star's fashion evolution and credited her wardrobe containing pieces that are simple and "more covered".
Speaking in this week's episode of Vogue.com's series, 'Go Ask Anna', she said: "Kim of all of them I feel has possibly changed the most.
"I personally admire the way she has become a little bit more minimal in the way that she's dressing and a little bit more covered."
The fashionista also praised the way the Kardashian family live their lives so heavily in the "public eye" and have still built a huge empire.
She added: "You have to admire how they have created an empire obviously through their personalities and creative genius of their mother [Kris Jenner]. And how they live the way they do, I can't possibly understand or fathom living so much in the public eye. But obviously it works."
Anna also praised 23-year-old catwalk model Kendall Jenner for "persevering" with her career when she was written off as just another reality star, comparing her to supermodel Linda Evangelista.