That's not far off from how young girls today look anyway. I cannot even fathom being as old as some young girls I see and wearing the crap they do. They seem to be developing earlier and uh, the majority of young girls seem to want to flaunt their goods. It's pretty gross. Whether they are having sex or not, their clothing looks like an invitation (not that it is, but it's extremely revealing and slutty) or a statement that, 'Yes, I am sexually active.'
But like duckduck says, I'm not sure how effective these will be at deterring sex with minors. No campaign is strong enough, unfortunately, to prevent early sexual activity. It's embedded into this generation of kids and teens. It's 'normal' (not necessarily meaning 'good') for people to have sex younger and younger these days.