In Portrait of Isidre Nonell, Ramón Casas uses a rich palette of warm colors, primarily deep reds and browns. The figure of Isidre Nonell is depicted with a thoughtful expression, his gaze directed slightly off to the side. The background is a soft blur, emphasizing the subject while creating a sense of intimacy.

The overall composition captures a moment of reflection, inviting viewers to connect with the subject's inner world. The painting is executed in oil on canvas, showcasing Casas' skillful brushwork and attention to detail. The texture of the paint adds depth to Nonell's features, particularly in the rendering of his hair and clothing. The dimensions are approximately 60 x 80 cm, making it a medium-sized portrait that draws the viewer in.

The use of light and shadow further enhances the three-dimensionality of the figure. Ramón Casas was a prominent figure in the Catalan modernist movement, known for his portraits and depictions of contemporary life. This work, created around the early 1900s, reflects the artist's interest in capturing the essence of his subjects. An interesting fact about this painting is that Isidre Nonell was also an artist, and their friendship influenced both their works.

Casas' style in this portrait marks a departure from traditional portraiture, embracing a more modern approach.