That’s the most fun explanation for this absurd advert in the September 18th issue of The Economist. It’s more likely that their ad department sent the wrong version of the ad copy and didn’t notice. If you look closely you can see that the entire pool is fake. Normally that wouldn’t bother me but they really dropped the ball on the effect here.
Anyway, take a look at the image below. I had to really double check to make sure I wasn’t crazy. Click on the image to see a high-res version.