"These views [referring to another painting in the same auction lot] of the Polo in Bagatelle, executed circa 1909, are preparatory studies for the Portrait of Léon Radziwill. See lot 233 for a preparatory drawing of the portrait." (http://www.sothebys.com/en/auctions/ecatalogue/2016/collection-boutet-de-monvel-pf1639/lot.263.html)