It's a classic retouching move, because if she were completely line-free it would be too obviously fake, while three wrinkles feels plausible in an aspirational way. Also in that playbook: Take out the sun spots, small scars, and pigmentation issues associated with pregnancy, but "leave a few freckles," to keep skin looking makeup-free.
Play down the nasolabial folds, minimize wrinkles all over the face, then keep a tiny cluster of "smile" lines around the eyes, to keep the subject warm and relatable, but not shriveled. The amazing thing is that it doesn't matter how many years over 35 a woman is, she still gets the three-wrinkle treatment. Whether you're Demi Moore at 47, Jennifer Aniston at 43, or Michelle Pfeiffer at 51, you get three wrinkles. Helen Mirren at 65 is allowed maybe five. To count yourself, see our slideshow of twelve celebs who got the "erase all signs but keep the crows feet" treatment. Then imagine the same for yourself.