- You can give it specific instructions and it will follow them, modifying its behavior by doing so.
This shows that the instructions are understood well enough to be followed. For example, if you ask it to modify its behavior by working through its steps, then it will modify its behavior to follow your request.
This means the request has been understood/parsed/whatever-you-want-to-call-it since how could it successfully modify its behavior as requested if the instructions weren't really being understood or parsed correctly?
Hence saying that the machine doesn't "really" understand, it's just "simulating" it understands is like saying that electric cars aren't "really" moving, since they are just simulating a combustion engine which is the real thing that moves.
In other words, if an electric car gets from point A to point B it is really moving.
If a language model modifies its behavior to follow instructions correctly, then it is really understanding the instructions.