Why is it difficult to tell whether the train is moving or not during a snowstorm?

Movement is a change in the position of some bodies relative to others. When, in normal visibility, we are traveling in a train carriage, we see that we are approaching some objects, we are moving away from others. It is also noticeable that the angle at which we see objects is constantly changing. On a snow-covered area with dense snow, it is practically impossible to select an object and notice a change in the distance to it or a change in the angle at which it is visible. From the moments of the flight of snowflakes, we can say that we are moving relative to them, but this does not interest us on the train.