Symbol is used in prophetic symbolic literature, and an image is used to express a philosophy, such as Aesop's Fables, which is a work that uses a lot of symbolism. This technique is very common in modernist works, such as Kafka's Castle.
The jar symbolizes the artistic imagination in the author's mind. Although this subjective force can give nature a new order, it cannot be divorced from reality. "Wilderness can symbolize a person's long-term chaotic mental state, and the jar is a mysterious touch (a person, an event, a scene), which suddenly enters life and secretly changes everything. The jar can also symbolize a lonely spirit, longing for a higher road. Before it came into being, it was a barren land, everything was peaceful, and it seemed that nothing needed to be changed; After its arrival, the wilderness was summoned by the lofty spirit and began to eagerly hope for change in order to get a new life.
Therefore, the jar is a symbol.