In ḥusn al-takhyīl, a poet constructs a scene that may be extraordinary or literally impossible, yet its parts cohere in the imagination and lead the listener toward the intended quality.
The device is not a pile of bizarre words. A successful image provides comprehensible associations: speed with rising dust, brilliance with light, or a long night with stars and sleeplessness.
Literal possibility of every detail is not required, but imaginative coherence and fitness to purpose are essential. Without them, novelty can become mere awkwardness.