Arrgg I get looks from customers at work and like, weird smiles I've never seen before so I have nooo clue if they mean, "Hey, I think I know this guy's dirty little secret", or if they mean "Hey, this guy's kind of cute". I always assume the former because the way I see it, if I were a hetero/bisexual girl (or bi/gay guy) I would NOT be attracted to me and would probably think I look funny.
But yeah I would guess she was commenting on your physical attributes. Next time something like that happens, shoot a good smirk or a charming smile and say hey.