It's more of like this: say you've got a nude model and a model dressed in a lingerie. The lingeries may or may not expose the crotch, but it doesn't really matter, either way it's more sexualized than the nude model. That's because the lingerie is placing focus on the genital region, whether it's exposed or not, by placing clothing in the area, while with the nude model all parts of the body are equally and naturally bare, whether the nude shaved their pubes or not.