Function of Metaphor: Poetry Practice Test

Read the following excerpt from an original poem:

At 2:13 a.m. the apartment hums—

fridge-light, streetlight, my phone’s pale tide.

I draft apologies I won’t send,

then delete them like footprints.

Anxiety is a smoke alarm with no fire,

shrill in the ribs, faithful and wrong.

What is the primary function of the metaphor “a smoke alarm with no fire”?

Read the following excerpt from an original poem:

I walk past the old playground,

its swings creaking like tired doors.

The paint peels in polite curls;

even the sand looks older.

Time is a locksmith with quiet hands,

changing every key while we sleep.

In context, what is the primary function of the metaphor “a locksmith with quiet hands”?