CLEAN : Da Vinci painting sells for $450mn in NY: Christie's

The transcript describes the auction of Leonardo da Vinci's masterpiece, Salvator Mundi, at Christie's. The bidding started at 350 million dollars, with active participation both in-person and via telephone. The final bid reached 400 million dollars, marking a significant sale in the art world.

Describe the atmosphere during the auction based on the text.

What does the phrase 'Well done' imply in the context of the auction?