Asīl denotes smoothness, delicacy, and graceful extension. In facial description it suggests a smooth cheek or refined facial contour. ʿAn asīlin thus pictures the revelation of an attractive feature.
Bi-nāẓirah brings the eye or gaze into focus, shifting the image from skin and coloring to the expression of looking. The poet does not equate the whole woman with an animal; he selects a specific quality of an animal’s gaze.
This is a form of selective comparison: first a smooth facial feature, then an alert look. The two images contribute distinct sensory and psychological effects.