The first three plagues punished the Egyptian gods, only from the fourth plague and on were the Egyptians themselves being punished. Therefore only from the fourth plague on was the difference between the Jews and the Egyptians very noticeable.

After Moshe shows up things only get worse. Why and what Hashem expects of Moshe in admonishing him for asking (very good) questions.

Introduction to the Sicha on למה הרעותה. The three ways Moshe met the Pharaoh. כה אמר הוי’… לא ידעתי את הוי’ה. אלוקים מול הוי’ה טבע מול נס. Egypt’s Parnassa is from the earth, Eretz Yisroel is fed from heaven. Pharaoh tries to show that all that Moshe does is from a G-d of nature and…

The first two plagues represent parallel yet opposite ideas: Dam- Blood is to warm Egypt from it’s natural coldness to holiness, to be warmed by it. Tzfardea- Frogs were to cool off Egypt’s passions to worldliness. Here the order (is atypical:) first from the top down and then from the bottom up.