Explaination:
That prints 'one' twice. It's iterating over the return value of each, so over a single $key, $value pair, printing the value of $key twice.
I think you misunderstood my post. I simply ran the OP's foreach code through the deparser to show how perl interprets the code. I simply showed the output of the OP's deparsed code. I did not suggest any new code.