whereas the ‘reader’ of a painting must attend just as closely to the material form of marks and shapes in the picture as to any ideas they may signify.
其中just as closely to the material form of marks and shapes in the picture as to any ideas they may signify.（as adv to n as to n）的意思是？省略了什么？补全是什么样？
attend to sth=pay attention to sth.
attend closely to sth = pay close attention to sth.
attend as closely to A as to B 像密切注意B一样密切注意A。
补全的比较分句为：
whereas the ‘reader’ of a painting must attend just as closely to the material form of marks and shapes in the picture as he attents to any ideas they may signify.
