Painter Shreds His Own Art Just As It's Sold At Auction

I'm an art lover even though I don't know much about it and I really don't understand this.A painting by the artist Banksy was auctioned off at Sotheby's in London on Friday for about $1.4 million . . . then immediately shredded itself.  It turns out Banksy had been planning it for years, and installed a shredder in the frame, just in case it was ever up for auction. Ironically, it might be worth even more now.  
 - Sally