Image viewer draws over active camera screen.

• ROM build version (date):
  All releases so far?

• Steps to reproduce:

I had this happen to me a few times by accident, and couldn't figure out how to reproduce it.
Till now.

1. Open camera app (Build-in, not a 3th party app)
2. Swipe right to open the settings pane on the left
3. Quickly swipe from the right side of the screen to the left (this might need a few tries)

As the 'previous photo taken', appears in the screen, the background (whilst should be black now) is now still "live camera image".

Example: http://i.imgur.com/uEZWXar.jpg