This story has been all over the news around here;
https://www.bbc.co.uk/news/uk-england-bristol-45770028
Essentially, famous graffiti artisy Banksy has sold one of his prints at auction for £1m. Immediately after it sells, the art shreds itself in front of everybody!
I'm not so sure though! It moves quicker than any shredder I've seen. The paper appears to change colour and I don't think the allignment is quite right between what's left of the original and the shredded piece out the bottom. Is this, in fact, a trick and the original is now folded up the back, with a pre shredded double fed out of the bottom?
Either way, it's a pretty impressive stunt and some reckon it has trebled the value of the piece instantly.

It is almost certainly just a publicity stunt. If you watch the video Banksy released of him building the "shredder" the cutting blades are side on and would not cut the paper as it scrolled through the frame.

The bottom of the shredded paper is curled slightly probably as a result of being wrapped around a roller used to scroll the paper out of the frame. As you say the alignment of the shredded paper does not appear match that of the original paper.

The seller bought the work directly from the artist, the buyer is unknown and the auction house workers were able to just lift the shredded work from the wall (surely such a valuable artwork so close to the public would be securely fixed to the wall). It has the smell of the KLF million pound destruction all over it.

The news report I watched said that Banksy did not want this work sold. They also said Banksy no longer owned the piece that was being auctioned off.

Although I cannot believe that the auction house did not inspect the art work and find the shredder set up in the frame.

Many things just to not add up.

I had not heard anything about Banksy not wanting it to be sold, he has after all sold a signed print before. But it does seem incrudulous that a respected auction house would not fully examine the work before the sale. If they did and they failed to spot a large slit in the bottom of the frame then it does not say much for their expertise