do you mean what do we think of them physically or first impressions.
For me personally, it would be their hair.
most likely in this order... this is what I notice (but not necessarily what I fancy)
1. His body language
2. His hair
4. Eyes- whether he gives eye contact or not
5. The conversation he strikes
6. Dress sense
the eyes, apparently you can tell alot about a person from staring into their eyes.
Overall facial expressions whether they think they are great or whether they are actually interested is mine. Posture that kind of thing then I go for looking at the physical.
the first thing i probably notice is a guys height! i like taller men and after that initial observation it is their overall facial features. i dont look for anything specific as long as they have an overall attractive face, if u get what i mean!
i think i read somewhere that the first thing you notice about a person is what gender they are. so, generally, i imagine the very first thing is that.
afterwards, a general physical impression - no real specifics, i just kind of evaluate how nice looking they are overall.
hair. always go straight for the hair.
eyes, then mouth (as in lips and teeth)
first thing i think is oh they are better looking then me...