Berndnaut Smilde regulated humidity, temperature and light to achieve this effect
This image is not photoshopped, it is Dutch artist Berndnaut Smilde's latest creation – the indoor cloud. His way of recreating a cloud has been dubbed one of the Best Inventions of the Year 2012 by Time magazine.The artist first had to identify what the proper environment would be for clouds to be created, and use that information to form indoor clouds.
Mashable writes that Smilde regulated humidity, temperature and light in the room to achieve this effect. He then used a fog machine to generate his clouds, in the middle of rooms, corridors and hallways.
His initiative is astounding and quite mesmerizing. However, recreating an otherwise common natural phenomenon does not seem like art. I can acknowledge to the exhibit's shock value, but not its aesthetic relevance.