Gain Self-Insight Through Abstract Thinking

I sometimes wonder whether it is better to ask for/elicit feedback from a near-complete stranger (first impression) or someone who already knows you (biased impression). From seeing video of myself at social gatherings, I unpleasantly know I give every impression of poor body language (slouch) but I'm not sure if I care enough to force my habits to alter.

Honest feedback is gold. To see yourself as someone else sees you seems to be a huge market covering everything from paid focus groups for new products to Alexander technique training to personal coaching to dating coaching where you practice approaching a female until she says you're getting good at it.

Perhaps that could be a way to monetize ChatRoulette. Pair people up to evaluate their first impressions with peer ratings evaluating how good someone is at evaluating a random stranger.

What I want to know is whether they over-rated or under-rated their attractiveness.