The song is a dramatic ballad, featuring an extended metaphor.

On another level, the novel is itself an extended metaphor for the way in which extrapolated futures are created.

By using an extended metaphor, it becomes more convincing.

An entire chapter turns out to be an extended metaphor.

This kind of comparison is known as an "extended metaphor."

I've been attempting to use this extended metaphor as the basis of a poem, but haven't quite cracked it yet.

The song uses an extended metaphor, using a woman to represent hip hop music.

Sunny Boy also uses extended metaphor to elaborate his lyrics.

Here the stems are reasonably certain, but they ignite an extended metaphor.

As a literary device, an allegory in its most general sense is an extended metaphor.