Why Do Brazilians Look White Why Do Mixed-race Brazilians Not Look Like Biracial Americans?

Why do mixed-race brazilians not look like biracial americans? - why do brazilians look white

the girl in this picture;
http://c1.ac-images.myspacecdn.com/image ...

is likely that the white piece of black, like many Americans, why many Americans are not looking biracial? I know many Brazilians, the mixed black / white, but has a distinctive look that distinguishes them from biracial Americans.