Al-ʿuthnūn is the hair growing beneath the lower lip or chin. Ṣuhābiyyah conveys a reddish or tawny cast, so the description need not be applied indiscriminately to the whole animal. It qualifies the hair specified in the phrase.
Al-qarā is the back, while mūjadah conveys strength and firmness. Together the expressions distinguish appearance from capacity: colour is observed in one area, while bodily solidity belongs to the back.