18. A Little Art Mystery of Sorts (Bazille, Again)

The painting within a painting that tells the story of a lost Renoir.

l’Atelier de Bazille, by Frédéric Bazille, 1870. Oil on canvas. Musée d’Orsay.

Update: This “mystery” has already been solved! (Although another mystery has taken its place.) I knew you guys would help. I have included the answer at the bottom, with many thanks to newsletter reader “Davy.”