As you may know, the Adsense program policies state that "Publishers may not place AdSense code on pages with content that violates any of [Google's] content guidelines. Some examples include content that is adult, violent or advocating racial intolerance.".
In other words, if you have user generated or user submitted content on your website you are responsible for making sure that all content, images and videos are compliant. Otherwise, you might get banned from the Adsense program.
To avoid that, you are welcome to run our Image Moderation tools on your images to detect any offending images. You can also request access to our Custom Web Crawler for a periodic monitoring of your website.
We're always looking for advice to help improve our documentation!