豸 is the Kangxi radical for crouching beasts and the indexing radical here. The connection to outward appearance comes via the head-and-body silhouette: 豸 originally depicted a creature pictured by its visible shape, so it became the natural radical for 貌 (face / appearance).
phonetic
皃mào
facial features
皃 (mào) is an older standalone meaning facial appearance — a person 儿 under a head 白. It supplies both the sound and the core meaning, making 貌 a doubled emphasis on outward looks. 皃 rarely appears today outside 貌 and 邈.
