How does Anne McCaffrey use imagery in Dragonquest?

Imagery:

"Suddenly she hissed, craning her head sideways, over her right shoulder, while her face reflected incredulity, horror, hatred. As suddenly, her body was seized with a massive convulsion. She screamed again, this time a mortal shriek of unbelievable terror and anguish. One hand went to her throat, the other batted at some unseen attacker. Her body, poised on her toes, strained in an agonized stretch. With a cry that was more gasp than scream, she whirled. In her eyes was Brekke's soul again, tortured, terrified. Then her eyes closed, her body sagged in such an alarming collapse that F'nor barely caught her in time.