What rhetorical devices are used in "but our frozen red flag can't fly in the wind" and what is its function?

Use the rhetorical method of contrast.

How magnificent the still red flag is under the reflection of snow. Set off the frozen red flag with the "dusk snow" coming down the Yuanmen one after another, set off "quietness" with "movement" and set off "red" with "white" to show the farewell feeling. The word "plug" is used accurately, which truly depicts the situation that the red flag is frozen and the north wind is not fluttering. This poem is strange and magnificent.

The words "and our frozen red flag can't fly in the wind" and "stop" mean that the wind is very strong, as if pulling the red flag. -Here, the wind is personified. But the red flag has been frozen by snow and ice, and it can't be rolled up any more. Snow and cold weather are vividly written. Snow can be reflected in "red" and cold can be reflected in "not turning".

Wisdom, pull. Write a farewell scene outside Yuanmen. The farewell banquet lasted until dusk, but when I went out of Yuanmen, I saw heavy snow. In this silvery world, a bright red flag stands out. This is a sign of China's military account, and it is also a sign that the border guards of Datang stood firm in the snowstorm. There is a little red on the vast snowfield, and the color is so bright. What a strange and beautiful picture it is. The north wind blows hard and snowflakes dance, but the red flag that has been fluttering in the wind is hard to hang, but it can't turn around. How thick the ice on the national flag is and how cold the weather is, everything shows that this is a world of ice and snow.