成唯識論演祕 4.142

4.142

答：於一切所緣作無量種差別行相轉故。釋同緣一質，相雖相似，見行各殊，名差別轉。

Answer: Because they operate producing immeasurable kinds of differentiated cognitive forms with respect to all intentional objects. The explanation states: while cognizing the same underlying entity, although the representations are similar, the cognitive forms of seeing are each distinct; this is called operating differentiately.