The scene on the cover is based on François Lemoyne’s masterpiece Hercules and Omphale painted in Rome in 1724 which had a lasting influence on many artists.
In the myth, Hercules was enslaved by Omphale, Queen of Lydia, for having murdered his friend Iphitus in a fit of madness, and soon afterwards became her lover. In the scene, Hercules, the classical hero is depicted holding a distaff and a spindle, being caressed by a seductive and powerful-looking Omphale who wears his lion's skin and holds his club while Cupid looks on witnessing what love can do to men. The essential feature is the exchange of attributes suggesting the idea of woman's domination over man, a subject absent from classical Greek art for its demeaning view of a legendary hero but found in Hellenistic times and later favoured in Baroque art.

Carved from a single stone, this style of boxes was especially common throughout the 18th century in England but especially in Germany where stones such as quartz and copper minerals were found in commercial quantities in Southern Germany. These boxes mounted à cage with mythological subjects were popular from about the 1740 to 1765 and mostly made in Berlin which was then the most important centre of production for hardstones boxes under the patronage of Frederick the Great.