Images that are covered with the new screen aren’t unavailable or deleted—users who wish to view them can simply tap on the screen. Instagram explained in a blog post announcing the feature:
Soon you may notice a screen over sensitive photos and videos when you scroll through your feed or visit a profile. While these posts don’t violate our guidelines, someone in the community has reported them and our review team has confirmed they are sensitive. This change means you are less likely to have surprising or unwanted experiences in the application. If you’d like to see a post that is covered with a screen, simply tap to reveal the photo or video.
Instagram began rolling out two-factor authentication in February 2016, and the safety feature is now available to all users.
Users who opt to activate two-factor authentication can do so via the gear icon on their profiles, and a code will then be required to access their accounts at every login.