Why US guys like bottom from horse ?

Take a look at Brianna Love from ATK Gallery, she was looking so cute:
http://galleria.amkingdom.com/02/images/models/brianna/brianna_sample.jpg
Now she's got ass cheeks from a horse and she's called Buttwoman, expand can't be from childbirth only, what happened ?
http://www.elegantangel.com/imgs/752f.jpg
And why do US guys like these monster cheeks, i don't understand ?
http://galleria.amkingdom.com/02/images/models/brianna/brianna_sample.jpg
Now she's got ass cheeks from a horse and she's called Buttwoman, expand can't be from childbirth only, what happened ?

http://www.elegantangel.com/imgs/752f.jpg
And why do US guys like these monster cheeks, i don't understand ?