Your analogy of AES being like a locked box was crystal clear and very easy to visualize. I particularly liked how you put it in terms of sending a box that only the keyholder could unlock; really puts the concept of encryption into real terms, especially for someone who might not understand much about technology. I also found it helpful how you related this to real-life applications like online banking and Wi-Fi protection; that shows how it impacts life. Your explanation balances simplicity with accuracy very well.