No, the secret to a great egg cream is very, very, cold milk; than seltzer under pressure so that it gets the thick, creamy, head; than good chocolate syrup poured in a thin stream through the center of the head, followed by a long teaspoon through the same spot you poured the syrup, stirring so that the spoon at the bottom of the glass is mixing the syrup with the seltzer/milk combo but not moving at all at the point in meets the white, frothy, head. Then you slowly remove the spoon.
That way the head stays frothy and white, with its very slight contrasting bitter taste, and the body underneath it sweet, fizzy and chocolate.
And THAT is a chocolate egg cream, Brooklyn style.