In Portrait of a Girl, Nicolaes Maes depicts a young girl with a gentle expression. The painting features soft colors, primarily warm tones of yellow and brown. The girl is dressed in a simple yet elegant garment, which adds to her innocence.

The background is muted, allowing the figure to stand out prominently. The painting is executed in oil on canvas, showcasing Maes' skill in capturing light and texture. The brushwork is delicate, particularly in the rendering of the girl's hair and facial features. Viewers can appreciate the subtle play of light on her clothing, which enhances the three-dimensional effect.

The dimensions are approximately 60 x 80 cm, making it a moderately sized portrait. Nicolaes Maes was a prominent figure in the Dutch Golden Age, known for his portraits and genre scenes. This particular work reflects the artist's ability to convey character and emotion through facial expressions. An interesting fact about this painting is that it exemplifies the shift in portraiture during the 17th century, moving towards more intimate and personal representations.

Today, it is housed in the Mauritshuis, a museum renowned for its collection of Dutch masterpieces.