yes, it is allegorical because we can see that it lacks the name of characters form which we can know that each character symbolizes something. This story might be the allegory of death where the hunger artist symbolizes the person who have lost interest from his life and choose the path to take fast as his art. Moreover this story might be about death beacuse this story ends with the unusual mode of death. Though it shows it is self-inflicted but it is done in unintentional way. And here the observer represnts as the society who doesn't care him and doesnt appreciate his art and the cage shows the restriction from the society.