The writer's comments are neither unchanging and bucolic. The word bucolic relates to the pleasant and unchanging nature of country life. I believe that this scene stay in one moment of time and not change. The writer's description of the rural scene with its fishermen, glossy black oxen and school children on bicycles represents forward motion. It can be inferred that the fishermen are busy fishing; the oxen are walking towards their destination, and the children are cycling to school. Everyone is doing something.
Another reason why this statement can be considered incorrect is that rural life isn't always pleasant. Extreme weather conditions can cause hardship and poverty for the people living in the countryside.
