Humans aren't the only animals to use illusion to their advantage. Butterflies, bullfrogs, facebook users, and PR departments exploit the heuristic shortcomings of other cognizers as well. Consciousness came late to the game and added complexity. Scientific method and technology added some more, along with sheer volume. While illusion can involve conscious processing, it doesn't have to (chameleons). While it can involve awareness on the deceiver's part, it needn't involve awareness that it's an illusion (selfie-uploading teenagers), or anything else outside what's necessary to pull off the trick.