iPhone has photos/videos which I didn’t take, has it been hacked? When looking around in my setting, General, or anywhere else in my iPhone 6 Plus, what is it I should be looking for, that could tell me my phone has been hacked? I already know it has been.

Someone has taken remote access of my camera. They accidentally left 6 recorded videos in my Saved pictures/videos, showing when they got the camera to innitially turn on, and showing as it zoomed in and out, even twitched the picture from one angle, to another in a single frame.

Things that are impossible for me to do myself? When I am operating my camera. Are there any specific terms/etc I should be looking for?
The camera can be used from the lock screen without unlocking the device. Access to existing photos is unavailable without unlocking, but new photos and videos can be taken without unlocking the iPhone. Your device has almost certainly not been ‘hacked’.

From the lock screen, swipe from right to left to access the camera. Photos taken here are added to your camera roll as if you’d taken them unlocked.