Final answer:
Seurat used Pointillism as a technique to create light and shadow effects in his paintings, which differed from the Impressionists' approach. He aimed to convey emotion and create harmony through his use of color and directional lines.
Step-by-step explanation:
The technique used by Seurat, called Pointillism, differed from that of the Impressionists in that he painted with small brushstroke dots of color placed next to each other and overlapping. This technique aimed to create the effects of light and shadow without pre-mixing colors on a palette.
Unlike the Impressionists, Seurat's approach was not solely focused on color or science, but also on creating harmony and conveying emotion in his paintings. Through the use of color and directional lines, Seurat hoped to evoke specific emotional effects in his viewers.