It has always puzzled me the difficulty of drawing faces. This difficulty lays on two fronts:
I write all this because I have been surprised by certain "failures" in the last week. These failures are, with some hindsight, well understood. First of all, those portraits were drawn from photographs, which implies some distortions that are accepted in pictures, but become stranger in drawings. Those are distortions due to the lenses, proximity of subject, etc, and the brain accepts them in pictures because they are compensated by the extra information available in other aspects, such as color, shadows, context, etc.
Second, people's faces are more similar than we get to believe. I showed the two portraits below to some people. They recognized the person in the second case, not in the first one. If you compare the pictures, which were drawn in A5, you will notice that the differences were nevver larger than a couple of milimiters in shape: center of the pupilis, right cheek, height of lips. Another important aspect is tone: the darkness of the hair makes a dramatic change and can change the context of our interpretation dramatically. Finally, the removal of lines on the nose, cheek shadows, crow's legs, etc, seems to make it more agreeable with our expectations.
After this, it is no surprise to me that women can so dramatically alter their appearance with a minimal application of makeup