it's not like I go around looking at packages or children's underwear, so I might be wrong...

That is part of the issue. Maybe they're all this bad? But I doubt it. It's certainly not something I want to research.

...but I don't think the kids on there usually 1) look like someone just tore half their clothes off of them, and 2) have these fucking looks on their faces.

That's the issue for me, too. The shirt tucked into the underwear, and the sweater or whatever half off. That's what gave me the immediate 'ick' factor. What the heck? If you need to show models in underwear for your ad*...do that. Why does it look like they were either stripping or, as you say, sexually assaulted? And, yeah, they look dead inside. The additional clothes make it creepier than if it had just been underwear.

* which you don't.