How it looks and feels is supposed to tell you how it works
So we have one arrow at the top pointing down, one at the bottom pointing up, text that ‘points’ right and then also a camera which points… nowhere (and is really small). Tap it, and the lock screen bounces. Hopefully people will divine from that that they can drag the camera up to take photos.
However, that leaves us with three drag indicators at the bottom of the screen, two of which are up! Good luck not triggering the control center when you’re trying for the camera.
When presented with an actual iOS 7 device, my first instinct was to slide UP to unlock, even though I’ve been sliding left-to-right since 2008. This use-cue is very misleading.