Rousseau's exaggerated stylization destroys individuality. His jungle figures are types: an African, an Indian, a woman. His Artillery Men are identical, The Football Players two pairs of clones. Wooden: they look like children's toy figurines. By simplifying to generality he strips figures of subjectivity. These are not persons, they're bodies. There's an analogy to Brecht's figuration of crowds.
This is one line through which classicism, that is, anti-Romanticism, reaches the 20th Century.