When a metaphor is continued throughout several lines of poetry called?

When a metaphor is continued throughout several lines of poetry, it is called an extended metaphor or sustained metaphor.

Here's what makes it different from a regular metaphor:

* Regular Metaphor: A simple comparison using "like" or "as" (e.g., "The sky is like a blue blanket.")

* Extended Metaphor: The comparison is developed over several lines, often with multiple points of reference.

Think of it as a metaphorical story that unfolds within the poem, creating a richer and more complex meaning.