The security of this encryption method seems to stem from the arbitrariness of the initial state S0. What is the difference between using the existing encryption method and appending a piece of random information at the beginning of the plaintext?

The security of this encryption  seems to stem from the arbitrariness of the initial state S0. What is the difference between using the existing encryption method and appending a piece of random information at the beginning of the plaintext?
But if you can't answer the above question, I can hardly see the significance of this research.