A more thorough explanation:

Definition: In Scots law, a white bonnet refers to a fictitious bidder at an auction who is employed by the seller to drive up the price of the item being sold. This person is also known as a shill.

• During the auction, the auctioneer noticed that the bids were not going as high as he had hoped. He then called upon the white bonnet to place a bid, which caused other bidders to increase their offers.
• It is illegal to use a white bonnet in an auction as it is considered a form of fraud.

These examples illustrate how a white bonnet is used to manipulate the bidding process at an auction. By pretending to be a genuine bidder, the white bonnet can create the illusion of competition and drive up the price of the item being sold. This can result in the seller receiving a higher price for their item, but it is considered unethical and illegal.