Since the question—What’s Christie’s Trying to Do to the Auction Schedule?—has been raised, it is worth adding the observation that this move is likely a harbinger of much more aggressive competition between the auction houses. The field of play is shifting from commissions and guarantees to broader thinking about who buys art, when and how. With Sotheby’s bringing in a new CEO who is backed by a bold activist with few ties to conducting business as usual and Phillips mounting a campaign to expand its market niche, almost everything about the most valuable sector of the auction market will come under scrutiny.

Most of the talk in the press has been about online sales. But the real opportunities—as Christie’s is demonstrating—come in addressing the needs and behaviors of the Ultra High Net Worth customers who are Christie’s, Sotheby’s and Phillips’s focus.

Christie’s seems to have moved their Impressionist and Modern sale for simple commercial reasons. The Venice Biennale presented a distraction and the firm had already built their weak around its “hybrid sale.” The late timing of the calendar move suggests the specialists were in touch with their clients and Christie’s calculated that its results—the firm’s most important marketing tool—would be better with the Impressionist and Modern sales moved later in the week.

There’s no reason to believe that Sotheby’s will be immediately hurt by the move. Their Imp-Mod Evening sale was slated to precede Christie’s. Now it comes 10 days earlier instead of one. How Sotheby’s will respond in the next sale cycle will probably be part of a much broader strategy change put in place by the new CEO. But the move does put Sotheby’s and Phillips on notice that Christie’s plans to move forward on its momentum and not wait to see what moves the other houses make.