well i just asked it the same thing and it gave me a 1MB 1024x1024 png with fringed edges & sensor noise that measures out to a 17x21 pixel image. https://files.catbox.moe/1q4jtp.png

In the time it would take to keep retrying until it makes one that fits, then reshaping it to fit into 16x16 nicely I could have just drawn one myself.