It's true that your opinion on someone else's physical appearance might not be the most reliable data point, but it's still valid. Everyone has their own personal preferences, which can be influenced by their age, income, and even the opinion of others. Having an opinion on the way something looks is a way to express your individual style and tastes. It's wrong to think that you shouldn't care about others' opinions on your physical appearance - by taking into account others' opinions and feedback, you can create an outfit or haircut that truly expresses who you are.