Eisen specialised in the Rococo style. His work often features playful putti and detailed ornamental motifs. In pieces such as Piece of Ornament with Two Swans, he demonstrates a mastery of symmetrical design and fluid line work. His compositions for Madame de Maintenon Returning to the Catholic Church show his ability to handle complex historical and religious subjects. He focused on clarity of form and delicate execution.

Modern collectors value Eisen for his technical precision and the lighthearted spirit of his subjects. His designs for book plates and small-scale ornaments translate well into domestic spaces. These prints provide a sense of historical character without overwhelming a room. Works like Putti with a Medallion offer a balance of classical geometry and soft, decorative elements.