1 The word “like” is added for clarity, making explicit the implied comparison in the statement “I have made you God to Pharaoh.” The word אֱלֹהִים (’elohim) is used a few times in the Bible for humans (e.g., Pss 45:6; 82:1), and always clearly in the sense of a subordinate to GOD—they are his representatives on earth. The explanation here goes back to 4:16. If Moses is like God in that Aaron is his prophet, then Moses is certainly like God to Pharaoh. Only Moses, then, is able to speak to Pharaoh with such authority, giving him commands.
2 The word נְבִיאֶךָ (névi’ekha, “your prophet”) recalls 4:16. Moses was to be like God to Aaron, and Aaron was to speak for him. This indicates that the idea of a “prophet” was of one who spoke for God, an idea with which Moses and Aaron and the readers of Exodus are assumed to be familiar.

In other versions

And the Lord said to Moses, “See, I have made you like God to Pharaoh, and your brother Aaron shall be your prophet.

Then the Lord said to Moses, “See, I have made you like God to Pharaoh, and your brother Aaron will be your prophet.

The Lord answered Moses, “See, I have made you like God to Pharaoh, and Aaron your brother will be your prophet.

Then the Lord said to Moses, “Pay close attention to this. I will make you seem like God to Pharaoh, and your brother, Aaron, will be your prophet.

And Yahweh said to Moses, “See, I have made you as a god to Pharaoh, and Aaron your brother will be your prophet.

And the Lord said unto Moses, See, I have made thee a god to Pharaoh: and Aaron thy brother shall be thy prophet.

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