Sherman upends images of wealthy people as invested only in accruing and displaying social advantages for themselves and their children. 

as invested only in accruing and displaying social advantages for themselves and their children 为比较分句，用作wealthy people的后置修饰语。

主句意为：谢尔曼颠覆了富人的形象，as比较分句用来说明富人是什么样的形象，as作为比较代词，替代了名词wealthy people，并在从句中作主语，谓语动词用过去时表示这是富人过去的行为。富人只在能增加和展示他们自己及子女的社会优势方面进行投资。富人的这个形象现在被谢尔曼颠覆了。

as引导比较分句修饰名词的其它例句如下：

This is a photograph of the church as it was in 1900.

Computer technology may make the car, as we know it, a Smithsonian antique.

关于as引导比较分句作名词修饰语，可参读Huddleston 《剑桥英语语法》CGEL P1150.