This kind of conditioning can take place without any mental reflection--we know this because humans can be conditioned this way without even being consciously aware of it.

This is not to say that the dog is unaware of having displeased their owner (which, as another poster pointed out, is in itself a form of mental reflection, although, as I responded, a very rudimentary one). It's just to say that the dog can be conditioned by this experience to not act that way next time, without being aware of it and without doing any mental reflection.