Answer
Impressionistic touch is the defining characteristic of Alfred Sisley's style. Sisley was a prominent French Impressionist painter who captured the fleeting effects of light and atmosphere in his landscapes. His works are known for their soft brushstrokes, vibrant colors, and ability to convey a sense of movement and immediacy. Sisley's Impressionistic style is widely admired for its poetic and evocative qualities, making him a key figure in the Impressionist movement.