What artistic techniques did Gu Cheng use in Lane?

The author's creative feature is the use of metaphor in poetry. Alleys, keys, walls, of course, are empty fingers.

It shows that people who have experienced the Cultural Revolution have been cheated and fooled, but the wall is compared to ugly forces or authoritarianism, the alley shows the way people are going, and the key shows a kind of hope. Liang has a song "China, I lost my key". However, Gu Cheng did not lose hope, and still stubbornly searched for the destination of life.

alley

It's curved and long.

There is no door

There are no windows.

I took an old key.

Knocking on the thick wall