The device shows up there because you connected to your computer and trusted the connection on your iPhone (and you had to type in your passcode to confirm.) If someone doesn’t know your passcode they can’t do this. If they do know it, they could access your photos anyway.
It’s probably worth filing a Feedback report to request Hidden photos don’t get served up over the standard file system access alongside the rest of your library. You can do so by typing applefeedback:// into Safari and hitting return. If you’re on a developer or public beta, you can simply use the Feedback app instead.
Definitely not a major plot point of the movie Shooter starring Mark Wahlberg.