The contrasting case is where resemblance rests on a quality that does not form a defining element of both concepts. Courage is not a necessary part of the definition of human being, and it is not what makes an animal zoologically a lion.
In raʾaytu asadan yarmī, the lion-name describes a brave man. Courage is the recognized point of resemblance, but it is not an intrinsic defining constituent of both categories.
A quality being familiar or striking does not mean it is internal to a concept. Calling such a feature external does not diminish the metaphor's rhetorical effectiveness.