Yea, rejection or shaming at the hands of a stranger doesn't mean much compared to that from a primary caretaker, or from a therapist playing a caretaker-like role. But that's because we are tribal creatures, and our brains are wired to equate survival with being accepted by the tribe, and with social status. To me the above quote is saying something about what happens in the brain when we are demeaned, rejected, ostracized by someone who is part of our tribe, or who maybe appears to be (therapist), as interpreted by our emotional/limbic brain. The rejection from my therapist seemed to be messing with my brain in the area of basic feelings of acceptance and belonging, and hence it had a survival-level impact.