She gave a slight nod before setting to work. She had plenty of other things to use on his face. Not that any of it would necessarily end up in the correct spot... She sat quite still, concentrating fully on her work of art. Ten minutes later she was done, holding up a mirror for her..."client" to observe her work.
He almost doesn't want to look in the mirror, but he does, because it seems that this is an inevitable, unavoidable part of being tolerated by someone close to Kakashi.
That doesn't mean that Gaara is happy to find his mouth liberally coated with about six coats too many of bright red lipstick (half of which isn't actually on his lips), or his cheeks dusted with entirely too much blush.
Struggling for a moment to find something nice-ish to say, Gaara eventually comes out with a strained, "You certainly have an eye for bright colors, Sakura-san."