Dr. Yueh (Visual Imagery)
Jessica studies Dr. Yueh's face, noting "the dark sequins of almond eyes, the butter complexion, the string mustache hanging like a curved frame around purpled lips and narrow chin." Visual imagery describes Dr. Yueh's appearance and uses visual associations to give an impression of his character. A lot of his appearance is described using inanimate and decorative imagery: his eyes are "dark sequins," his mustache is "string" and a "frame." Inanimate associations might indicate his artificial loyalty. His "almond eyes" and "butter complexion" are next to each other, emphasizing the consumable nature of Dr. Yueh's appearance, perhaps indicating his connection to the gluttonous Baron who will ultimately kill him. (It's worth noting that, while it likely wasn't deliberate on Frank Herbert's part, using food as visual imagery to describe someone's complexion is associated with racist writing in today's literature.)
Leto is drugged (Haptic Imagery)
Haptic imagery is used to describe Leto's experience while drugged: "Leto could feel the chains, the ache of muscles, his cracked lips, his burning cheeks, the dry taste of thirst whispering its grit in his mouth. But sounds were dull, hidden by a cottony blanket." The touch-based images here of aching, cracking, burning, and thirsting create an uncomfortable sense of being stuck. His sense of hearing is similarly stuck, as he's trapped by both chains and the drug.
The desert at night (Auditory Imagery)
"He inhaled, sensed the softly cutting contralto smell of sage climbing the night... a stillness to the basin so unutterable that the blue-milk moonlight could almost be heard flowing across the sentinel saguaro and spiked paintbrush. There was a low humming of light here more basic in its harmony than any other music in his universe."
Paul's narration uses a mix of visual, olfactory, and auditory imagery to give a synaesthetic, almost hallucinatory impression of the desert at night. Smell is described as "contralto," the lowest female singing voice; the moonlight can "almost be heard flowing" with a "low humming." Light is directly compared to music. By using auditory imagery to describe things that are seen and smelled, not heard, Herbert invites the reader to imagine an immersive single image with all of their senses.
The Fremen sietch (Olfactory Imagery)
Paul smells a Fremen sietch for the first time: "The odor of the place assailed him: unwashed bodies, distillate esthers of reclaimed wastes, everywhere the sour effluvia of humanity with, over it all, a turbulence of spice and spicelike harmonics."
The olfactory imagery used here is certainly overwhelming and unpleasant, as it "assails" Paul with "sour," "unwashed," "turbulence," and "wastes." However, part of the overwhelming odor is communicated by the less-common vocabulary used—it's likely hard for the reader to immediately recall the smell of "distillate esthers," "effluvia," or "spicelike harmonics." The smell is overwhelming, and the olfactory confusion is communicated by both plain language and disorienting, hard-to-imagine jargon.
