1) As we all know Adsense doesn't like NSFW images as their Ad network publisher host. It would be a great idea to provide a tool to admins to mark NSFW images/user accounts so that we can serve alternate ads on those images.
2) Additionally, Please show a checkbox on upload form to state that those images are NSFW.
3) Allow admins to be able to choose whether or not show the NSFW images in public image listing where recent images are shown from users across the site. Users who wish to see NSFW images in their listing can enable it in their account settings.
All these features will help us provide a safe publicly appropriate environment where users can access the website without fear of being bombarded with nude images. If it is not implemented as soon as possible, it will only degrade the reputation of the website over time. Serious users will abandon the website the first time they encounter such issues.