probably because mostly models dont wear too much make up on her free days but she use lot of times for events and photoshoots if its required.
source: marieclaire.com
Nina: I don't really wear a lot of makeup, but before I get off an airplane, I use some Laura Mercier Foundation Primer in Radiance, and I just love it. It instantly makes your skin look glowy and dewy, which I personally love. Then, a little concealer, curling the lashes, and some mascara. That's my go-to. I normally do that on the plane before I walk off and that's it.
MC: You spend so much time working out. Do you wear makeup then too?
Nina: I do wear makeup when I work out. I am one of those people. It sounds stupid, but I can't really get motivated if I don't have a mirror and I'm not staring at myself because I need to look at myself. I'll see an area that I'm not happy about, everybody has one, and I'll just work harder and bust it up. So I like to keep my face "pretty" because then I won't be like oh my god, what are you doing here?