“Nobody wants to be asked to sell something that isn’t going to sell well,” Ottilie Windsor, the co-head of Sotheby’s upcoming sale of modern and contemporary art in London, told me recently. She was previewing the sale, but also keenly aware of the market’s equivocal mood some two years into the dip. Tom Eddison, her partner in producing the sale, spoke of “renewed energy and optimism” and “positive green shoots for the year going ahead,” but that didn’t necessarily mean it was easy to procure works for auction in this uncertain environment. Windsor recounted how the duo had to make compelling arguments to consignors. “We’ve looked for things we think the market wants,” she told me. And they’ve backed some of those key lots with irrevocable bids, which reminds the market that a buyer already exists.