How about a nsfw flag. The interface can judge from a stake weight sum and user sets a threshold for hiding it. It incurs no cost but decays fast like voting power, to stop attempts to use it as a censorship tool. And SFW flag next to it that counts the other way.
I think it would be interesting to see how it gets used. Is fakenews and pizzagate nsfw? I think so, sometimes the images are very disturbing. The images could be hidden instead and just the headline and first line, rather than completely hidden at option.