First of all, the snake was considered a wise and magical creature in Egypt, and it came to represent the power of Pharaoh himself. It makes sense that God's first statement to the king was a challenge to his religious and mystical authority in the eyes of the people.

Secondly, Pharaoh's magicians would have been specialists in spells and incantations, as well as being well-versed in omens and dreams. They would have practiced sympathetic magic (the association between an object and the real thing it symbolized), and would have used their powers to command the occult spirits. There is no reason to believe they were showing off with some sleight of hand (a cobra that became stiff when grabbed in a certain way). These magicians were masters of the occult.

When Aaron's snake swallowed the Egyptian snakes, it would symbolize an Israelite triumph over Egypt, and a triumph of the true God over the spirits of the occult.

So in a sense, the answer to your question is "yes, sort of." Pharaoh's gods were real spiritual forces, but false as god since their power was not all-powerful and they lacked the other characteristics of true deity. Thus they portrayed themselves as gods, but were fakers, wanna-be's, and imposters to the throne, so to speak.

In the story of the Exodus, where Moses and Pharaoh throw down their staffs and both staffs turn to snakes, even though Moses' staff won, doesn't that suggest that the Pharaoh's gods are real, just weaker than God?