Presumably, its origins lie in the belief that blushing, eye contact, ugliness, and body odor are noticeable and troubling to others
I think i can identify with this statement. I often feel that people dont want me to be around them because of the way i look - like my ugliness offends them.
To make matters worse i think there is actual evidence of ths being true. I remember a few years back reading about a high-end hotel in NYC that was popular with the rich and famous. They fired a few of their staff because they only wanted to have attractive people serving the dining rooms (where all the glitterati were). They claimed that the ugliness of these particular staff drove the famous clientele away, and that beautiful people only want to see other beautiful people. I believe they brought a discrimination suit against the hotel but did not win because "lookism" isnt a defined form of discrimination. I think one of them won his job back because he was latino and he was able to use that as a basis for discrimination, but not his actual 'ugliness'.
Of course i dont have the site for this, but, i did read it and it has forever been stuck in my mind.