His approach relied on technical precision and a sober colour palette. Neuman avoided the dramatic flourishes of the Romantic movement, preferring a realistic style that recorded the physical details of his subjects. In his portrait of the poet Jacques Perk, he captures a sense of individual character through careful attention to the face and posture. His paintings of artists and dealers, such as Johannes Cornelis van Pappelendam, document the cultural circles of Amsterdam.

These works appeal to collectors who appreciate the clarity of 19th-century realism. Neuman's portraits are direct and lack the clutter found in many Victorian-era paintings. The subjects appear grounded and real, making them effective additions to a gallery wall or a study. His prints provide a sense of historical continuity and a glimpse into the faces of the people who shaped Dutch society.