This notion is everywhere and it's just dead wrong. It's still possible to think in the presence of biases. The fact that your opinion may be subject to some unconscious biased in some direction does not invalidate your opinion. Maybe it weights it in a way you're not aware of---but maybe not. Maybe they are fully aware of the fact that they could have some bias here but have enough data to think that their observation is still true in some significant way.
This notion is everywhere and it's just dead wrong. It's still possible to think in the presence of biases. The fact that your opinion may be subject to some unconscious biased in some direction does not invalidate your opinion. Maybe it weights it in a way you're not aware of---but maybe not. Maybe they are fully aware of the fact that they could have some bias here but have enough data to think that their observation is still true in some significant way.
Given that it fit a pattern of commenting on what he perceived in all the other portraits, what exactly would you have had him do?
He obviously isn't lacking in self-awareness. He was upfront about his possible bias.