[Cognitive]

I believe, at least in some cases, there is a biological aspect to this condition akin to OCD. Its an inability to cope with uncertainty. Each look in the mirror may produce a different result, so the sufferer copes by engaging in the ritual of repeated looking in an attempt to reassure themselves. You never really get there and, even if you do, its only ever temporary. In my experience, I firstly accepted the thing(s) I didn't like myself (counter-intuitive) and then began preventing this cycle. It did feel like a weight off my shoulders and giving the mind a bit of space helps it gain perspective.