Did you know that Facebook has a crawler which looks at images on the page on the other side of a posted link?

https://www.theguardian.com/technology/2020/jun/13/facebook-incorrectly-removes-picture-of-aboriginal-men-in-chains-because-of-nudity
Once, they got in hot water for censoring an article from The Guardian (rebutting a claim by the then Prime Minister who claimed that slavery never existed in Australia) for "containing nudity".