Alphonse Mucha's recurring female figure is often treated as a unified Art Nouveau type, alternately interpreted as an erotic commodity, a decorative ideal, or an emblem of the New Woman. This article argues that the category becomes analytically unstable when it is applied to the theater posters Mucha designed for Sarah Bernhardt. Through close visual comparison of Gismonda (1894), Lorenzaccio (1896), Médée (1898), and Hamlet (1899), with JOB (1896) serving as a commercial countertype, the study develops the concept of ornamental invariance: a stable graphic system that preserves celebrity recognition while role, costume, narrative action, and gender change. Mucha's elongated format, architectural enclosure, shallow stage-like space, integrated typography, and repeated inscription of Bernhardt's proper name do not simply feminize the performer. They make her legible as a serial star persona across Byzantine noblewoman, male Renaissance conspirator, murderous mother, and Shakespearean prince. The cross-gender posters are therefore decisive. They reveal that visual continuity in the Bernhardt corpus belongs less to a generic feminine icon than to a named performer whose identity could contain unstable gendered roles. By contrast, JOB fuses an anonymous smoker with a product name, erotic pleasure, and commodity recognition. Distinguishing the named theatrical persona from the anonymous commercial type revises the gender history of Mucha's posters without presuming that visual prominence equals historical emancipation or that all viewers received the images in the same way.