Marie Thérèse Geoffrin was a particularly famous Parisian salonière. On Mondays she held an artistic salon attended by such luminaries as the architect Jacques-Germain Soufflot and the painter François Boucher; Wednesdays were reserved for her literary salon, where the guest list regularly included Voltaire, Diderot, and Montesquieu.

The ease with which Madame Geoffrin sits (in the standard three-quarter-length pose) and the graceful gesture of her free hand suggest that this woman is indeed perfectly comfortable socializing with the greatest minds of eighteenth-century France. To emphasize further the importance of her sitter, Loir has gone to great pains to convey the sumptuousness of the lady's costume. She carefully picks out each detail of the complicated pattern in her satin dress and in the pearls decorating Madame Geoffrin's hair and fur-trimmed red cloak. The artist seems equally at home with richer, more painterly passages, such as the folds of that cloak, as it falls over the sitter's shoulders and hips. Especially impressive is Loir's treatment of the salonière's delicate striped veil, which cascades down her back. The dark monochrome interior and glimpses of a heavy brocaded chair are standard for this period. What sets this portrait apart from other contemporary examples is Loir's obvious refusal to idealize her subject beyond recognition. Although she is an attractive and thoughtful woman, the soft flesh under Madame Geoffrin's chin hints at the onset of middle age, a detail most fashionable male and female portraitists would undoubtedly have omitted.