How does Isaac Asimov use imagery in Foundation and Earth?

Imagery:

"It is easy to argue that a society that depends totally on robots becomes soft and decadent, dwindling and dying out of sheer boredom or, more subtly, by losing the will to live."

"'After all,' and here Trevize felt a sudden twinge of trouble, which he forced himself to disregard, 'it is not as though we had the enemy already here and among us.' And he did not look down to meet the brooding eyes of Fallom - hermaphroditic, transductive, different - as they rested, unfathomably, on him."