If you watch the clip again https://replay.reallifecam.com/view/20_17?ts=1536950510&from=share
You will see that there is no black cable plugged into the socket, there is something plugged in but it is not a cable. Also the night vision was already turned on before she pressed the button, if you look at the image you will see that it was black and white, then when she turned on the light as she entered the room the camera went back into normal color view, it takes a few secs before it switches from NV to color, same way when they turn of the light at night it takes a few secs before the NV is on.