Sites nearest competitor(also running adsense) has a full nude on the home page, of a pregnant woman.
Adsense only warns you when someone has reported a photo.
When I started with Adsense (9 years ago) and I was a newbie, I told a friend about my project. He was so thrilled with the idea of getting some money with a website, he said he could make his own website, and asked me for help.
I ended up lending him my Adsense code (I really don't know why).
He started making a website about Argentinian models. I checked, and it was fine.
But Argentinian models are known to be kinda of... sometimes they are a step away from being Play boy models or soft core models. While there were no nude photos, or even hot photos, there were a couple that were in the gray area.
For 3 years, the site had no problem. (My friend just worked on it once, got bored, forgot about it). The site also had little traffic, and would have made 15 cents per day.
One day, I got warned for a photo of a girl in a bikini, standing, showing her back and behind. It was not even a thong. But Google has zero tolerance when something is reported.
Since then I keep everything on my sites family friendly. And I've never shared my code again.
@nippi You should report, with your personal account (or "another), your competitors' "unacceptable" photos. Fair is fair. All rules should apply to everyone.
You can flag the photos, and then report to the Google Adsense Infringement Dept.