Here a quick summary about what we discussed together on the
telephone regarding the showbox, and the 'consolidation' of it with
Boris for STK.
In the showbox the following should implemented/changed:

• Closing showbox on key escape
• Going to the previous/next image over the keyboard arrows too (not
  only the href's of prev/next).
• Clicking besides the showbox onto the grey scaled background/
  origin page, the showbox should close.
• When no previous or next image is available, the pre/next should
  not appear. Best would be if no href would be generated at all, if
  no next/ prev is available.