How does Frank Herbert use imagery in Heretics of Dune?

Imagery:

"Failure was inevitable, though, and Lucilla knew it even as she ran. The Face Dancer had only to shift his weapon into full burn at close range. He could lace the air in front of him. Nothing could penetrate such a defense."

"The planet Gammu's bright midday sunlight bounced off the white courtyard walls filling the area beneath them with brilliance as though a spotlight had been directed onto the young ghola."