The OS notifies the app after the screenshot is taken. The app doesn’t get to do anything in response to it being taken or allow it to be blocked.

They’re abusing an iOS text rendering control function handled by the OS. Before the screenshot is taken iOS swapped out the rendered text for “sensitive” fields and images that.

The replacement is supposed to be something like a masked account number, password asterisks, or just general blur.

Not a marketing logo.

It's wrong. iOS sends an event on screenshot.

https://developer.apple.com/documentation/uikit/uiapplicatio...