How to Look at and Understand Great Art Lectures Episode 4 Line—Description and Expression ( Air Date 2011-01-01 ) Genre Documentary category. Overview "Discover the properties of line, another essential element of art, as "descriptive" (describing reality) or "expressional" (conveying feeling). Learn about the use of geometric lines, implied lines, and directional lines within a composition. Also, study the compelling, psychological use of line in Picasso's works, Seurat's "The Circus", and in key Modern and Expressionist works.".