What do you mean or what does a girl look like when you say she is average, pretty, or beautiful?
Most Helpful Girl
Not sure if you just wanted guys to answer this, but here's how I see it -
Average is just a girl that blends in. She can be any body type, have any kind of hair, whatever, it doesn't matter. The main thing is these sorts of people are usually very quiet and passive, so they aren't noticed for their personality, and they do not have any striking features that make them stand out for their looks. A girl can be average looking but still get attention because she has a fun personality. Usually, average people just try to fit in/are scared of standing out.
I think of a lot of actresses would be considered pretty/sexy. I think a pretty girl has good physical features, but isn't "drop dead gorgeous" or doesn't have a certain quality that makes her stand out. This is just me, but I think a lot of the time a pretty girl is someone a guy could see himself sleeping with or bragging to his friends about upon first seeing her without having a desire to get to know her/seriously date her. In a way, I almost think pretty girls have it just as hard as average ones do--an average looking girl that stands out for personality is still interesting, while people might automatically assume a pretty girl is easy and doesn't have to be intelligent to get people to notice her.
To me, I usually find models beautiful. I think a beautiful girl isn't necessarily sexy, she just has very striking features. Have you ever heard of the model Agyness Deyn? Many people I know find her very beautiful but not sexy. A girl who's beautiful just by physical appearance is rare, and they're the sort of people that compel you to get to know them just because of how in awe you are of the way they look. A girl with a great personality can become beautiful over time though, so if you hear someone say, "She is a really beautiful person," it's usually based on the kind of person they are, not only because of what they look like, if at all.
Whew, that was long!