The Optical Illusion World

On the first day Hashem says "let there be light," and there is light. On the second, He says it and then "made" the Rakia. On the third He tells the land to bring forth grass, and the Torah adds that fruit and vegetables carry their own seed. Why does each day of Bereishis put one more step between Hashem's word and the result? And what is this setup meant to test in us? A mashal about villagers who rebuild a train, car by car, is about how easily we miss the first link.