Even if it was 'slutty' (which in terms of a facial expression would really just mean a seductive look ANYWAY) it makes me sad every time someone talks about slutty as a bad thing.
"Slutty" when used negatively is usually just a word used by people who are uncomfortable with any expression of sexuality :/
I agree with Poyanyo, I think this figure's expression looks devious/sly most of all. Like she's plotting something. But I don't see what would be so awful about a seductive expression... Lots of Miku figures look very innocent so this kind of a change is nice, as would be a more seductive/mature look. I like variety.
(Also, Bloody, do not order from Nin-Nin Game as they've been shown to be scammers in the past.)