Ask HN: Is iOS 18 Screen Mirroring a backdoor?

This new iOS 18 feature lets you use your "turned-off" iPhone without ever inputting your PIN code. To me this is the exact definition of a backdoor.

It's true that this is only possible when you're logged into a computer that is logged into the same Apple Account, but this setup feels eerily similar to the ability by Apple to use your phone remotely.

Are my worries unfounded? I feel that Apple should secure this better or at least explain how this is already secure. Their help pages are very vague on this.