Day and night is the difference between the art auction of today and 250 years ago. The two pictures displayed at the top of this Wiki page depict some key distinctions. Modern technology is now a big part of the bidding room - microphones, speakers, TV screens, and projectors showing the artwork are all present. There is no great need to display the work that is being sold off during the auction. Also, the modern auction allows for telephone and web based bidding. It also seems that the current day auction is a lot more organized and controlled.
The modern auction has it's own kind of branding and marketing. What I mean by that is it seems the auction is as much about the star power of the auction house, its auctioneer, and its clientele, as it is about the work being auctioned. It looks so easy to get caught up in the moment and spend more than you ever wanted to – which I believe is a product of successful marketing by the two major auction houses.
An example of a recent and notable sale is Roy Lichtenstein's I Can See The Whole Room...And There's Nobody In It! It sold for $43.2 million at Christie's in November, 2011. 
Here is a video of the piece being auctioned off at Christie's:
After watching this video of the piece getting auctioned off, I realized how well the reading describes the typical auction. The Lichtenstein piece was auctioned off at Christie's by Christopher Burge. His charming personality as described by Thornton is seen in the video. While he does seem to have "tight control over the room" (Thornton 5), he has a way of engaging the crowd that keeps everyone involved, whether or not they are bidding. I think any major auction ar Christy's or Sotheby's is really well described by Thornton who calls it a "high-society spectator sport" (Thornton 9).
Burge does a good job at spreading the energy throughout the bidding room. "People who buy at the auction say that there is nothing like it: your heart beats faster, the adrenaline surges through you" (Thornton 10). Also, its interesting that he knows some of the bidders by name. In the reading, Thornton explains that before the auction, Burge studies the background of the potential bidders. Although Thornton mentions that Burge has a script to read from, it doesn't seem like he is doing so. The auction "crowd is international" (Thornton 12), which explains the display shown in the Lichtenstein sale video that has many different currencies. Burge, with his British accent, makes a good auctioneer as it brings a sense of Europe to the American auction.
Does anyone else think the excitement generated by a high profile auction in and of itself causes people to bid higher?
Here is a link to a website in which Sarah Thornton comments on the Lichtenstein sale: http://blogs.reuters.com/felix-salmon/2011/11/21/why-you-cant-always-trust-auction-results/
Here is a link to a Wall Street Journal article about the sale: http://online.wsj.com/article/SB10001424052970204190704577026963186239408.html