In La Trappistine, Alphonse Mucha presents a serene figure, likely a nun, draped in flowing robes. The colors are soft and muted, with a palette dominated by earth tones and gentle pastels. The background features floral motifs, typical of Mucha's decorative style, enhancing the overall tranquility of the scene.

The figure's expression is calm, embodying the essence of peace and contemplation. The painting is characterized by its intricate details and ornamental elements, hallmarks of the Art Nouveau movement. Mucha employs a smooth application of paint, creating a delicate texture that enhances the figure's features. The composition is balanced, with the figure centrally placed, drawing the viewer's eye.

The use of line and form is fluid, typical of Mucha's signature style. La Trappistine was created during a period when Mucha was deeply influenced by the decorative arts and the feminine ideal. This work reflects his fascination with the beauty of women and the spiritual qualities he associated with them. An interesting fact about this piece is that it was part of a series of works that celebrated the role of women in society, showcasing their strength and grace.

Mucha's unique approach to portraiture has made this painting a notable example of Art Nouveau art.