Why did George Seurat spend two years trying to perfect black and white drawings?

This is a picture i'm drawing for my art class! i need to know if it good (first of all) and that it represents dia de los muertos (

Which character of art pop art in roy lichtenstein’s artwork choose all that are correct it is inspired by america it depicts by american culture it has delicate lines and detailed shapes it is printed with bold colors and shapes

I’ll mark brainliest, i need some , someone me