This is an advertisement found in a publication of the magazine “En Route” dating from 1937.
“En Route” was a luxury magazine dedicated to the automobile which appeared quarterly and which included both particularly studied illustrations and in-depth articles.
Incidentally, one will recognize, at the foot of the page, under the brand Henri Chapron Carrossier, the profile of the Delage D8-120 – Cabriolet of which a specimen appears in the collection JWA Classic.