How does Geoffrey Chaucer use imagery in Troilus and Criseyde?

Imagery:

"Criseyde this lady's name; and, as for me, if I may judge of her, in all that place there was not one so beautiful as she, so like and angel in her native grace."

"He had supposed that nothing had the might to steer his heart against a will as free as his; yet, at a look, immediately, he was on fire, and he, in pride above all others, suddenly was slave to love."

"There, on the collar, could he not perceive the brooch he'd given her when they had to sever, yes on the very day she took her leave, in memory of his grief and him for ever? Had she not pledged her faith that she would never part with that brooch? But that was long before; He knew he could not trust her any more."