The familiar, comfortable realism of this painting is characteristic of the portraits of the 1870s, but the composition is highly original. Indeed the model appears in a three-quarter view with her head turned away and seems to be glancing at herself in the mirror before she goes out. The reflection therefore seems to be looking straight at the spectator, who is caught in the centre of a complex series of glances from Berthe-Marie to the spectator via the mirror. The mirror, symbolising the virtual and the illusory, short circuits the depth of traditional perspective. Central to the composition and the dynamic it creates, the reflection is swiftly brushed in black whereas the model is more precisely painted and more carefully worked over.
　Whereas the academic painters focused on rendering the costumes, as the very official artist Henner did in his portrait of Madame Jeantaud, or rather of her dress, Degas transformed the genre with this highly original, lively image. 
　A transitional space between realist painting which imitates the real world and synthetic painting which offers another reality, this painting triggered Degas' research into multiple viewpoints of the same object, an approach which seems to presage the Cubist portraits of Braque and Picasso.

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　About 1875, Degas made a portrait of Berthe-Marie Bachoux, Jean-Baptiste Jeantaud's wife, who had been the painter's comrade in arms during the Franco-Prussian war in 1870. In 1929, she bequeathed another painting by Degas to the Musée d'Orsay: Jeantaud, Linet, Lainé (1871), in which her husband appears with two friends.

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