Can you guess what it is yet?
A picture paints a thousand words, apparently.
Imagine then, the particular thousand words you would choose to say to your child, after he or she had painted this on the roof of your £1 million Berkshire mansion. His parents have some time to ponder this, as their budding artist offspring is away travelling at the moment. Wouldn't you want to be a fly on the wall when he gets back? (Unless the wall is decorated in a similar fashion to the roof, obviously.) I was going to say you don't have such problems if your kids want to be copywriters, but there are probably a few words you wouldn't want on the roof of your mansion too.
No, I didn't believe it either. But you can find the original story here. First one to find the house on Google Earth and email me gets a lollipop.