In tarshīḥ, a metaphor is supported by details appropriate to the borrowed comparison image. Such elaboration reinforces the figurative picture rather than necessarily creating a separate comparison.
If a brave human is figuratively called a “lion,” further references evocative of the lion can strengthen that metaphorical portrayal. The added details do not automatically become individual technical similes.
The crucial distinction is between reinforcing an existing borrowed image and explicitly establishing a new comparison between two things. Tarshīḥ belongs to the former analytical function.