"Sketch" is to draw a vivid image with the most concise pen and ink, without contrast.
Contrast refers to the use of sub-images that are opposite and different from the main image to set off the main image from the opposite side. The main object (body) and the supporting object (body) have opposite characteristics or different situations, so the body is used to set off the body from the opposite side. Function: express the theme more vividly through comparison.
Reference/Articles/Early Departure /3549 128? Fr = Aladdin content, very detailed.