The document discusses the rule of thirds composition technique used in the creation of a billboard advertisement. The rule of thirds involves dividing the visual space into thirds both horizontally and vertically, creating nine equal sections. Positioning the primary subject off-center and at the intersection of these lines makes the composition more interesting and eye-catching compared to a centered subject, drawing the viewer's attention and revealing additional elements of the scene. The author applied this technique in their billboard by placing the silhouette of a person on the left third to highlight notes and headphones in the background.