That image is also on their website, and is posted above. The site can be viewed in either Dutch or English.
I'm totally at a loss as to why they did this, as even trolling their site I couldn't get a clue. There is, I'm sure, an esoteric reason for it. The summary of the production says:
The third part of Ivo van Hove's version of Wagner's Ring cycle will, once again, be a both intriguing and moving present-day interpretation of the work.I did notice, however, that tickets appear to still be available for all showings.