Well, she's 43 now, and very thin and low body fat generally = looking older. I notice she's had some filler put in her cheeks (that little dimple at the outside of the lower eye/upper cheek area is a giveaway).
Also, she must've had a pretty stressful time recently with the imminent launch of her TV show and ARO rebrand, and the relentless barrage of negative press aimed at her. First there was the Hollywood Reporter, then The Cut, and finally that huge VF article in December. Surely even the most teflon-coated person would surely find being on the receiving end of that quite hard to live with?