Sensitive image and video warnings
The Sensitive Content Warning helps adult users avoid seeing unwanted nude images and videos when receiving them in Messages, via AirDrop, in a FaceTime video message and in the Phone app when receiving a Contact Poster — all using the same privacy-preserving technology at the core of Communication Safety. The feature is optional and can be turned on by the user in Privacy & Security settings.
Set up a Sensitive Content Warning on iPhone, iPad or Mac
Do one of the following:
On your iPhone or iPad: Go to Settings
> Privacy & Security 
, then tap Sensitive Content Warning.On your Mac: Choose Apple menu
> System Settings, click Privacy & Security in the sidebar, then click Sensitive Content Warning.
Turn on Sensitive Content Warning.
If Sensitive Content Warning determines that you’ve received a photo or video that appears to contain nudity, it blurs the image, displays a warning that the content appears to be sensitive, and offers ways to get help.