The first new aspect about Hosea 4:1–19 is that imagery (the image of marriage) is no longer used. The sin of the people is now being pointed out very concretely and in detail. In Hosea 4:6 the essence of their sin is discussed.
Another new aspect is that now there is a particular focus on the leaders of the people. In Hosea 4:4 and Hosea 4:6 the priest is mentioned. The priests must lead by example, but the opposite is happening. And the result: like priest, like people.
1 Hear the word of the LORD, O children of Israel, for the LORD has a controversy with the inhabitants of the land. There is no faithfulness or steadfast love, and no knowledge of God in the land;