Comment by fho

Not an expert, but my intuition is that most of the sketch artists job is asking the right questions. I would assume that most people would have trouble describing close friends or even their partners from memory.

Somewhat tangential: the "part of the brain" that is responsible for recognizing faces is incredibly well developed. That "peek-a-boo" game that you play with children? Every time you uncover your face millions of neurons in the childs brain suddenly fire giving them a jolt of "joy". The face recognition is so developed that we tend to see faces were there are none (face pareidolia).

... the point being that the brain does a lot of unconscious work recognizing individuals. Describing those individuals later consciously is pretty error prone.