People should not feel compelled to tip anyone because they rang up an order. Table service is a totally different matter.
I haven't watched the video, just saw a clip of her sitting at a table talking to one of the supposed “common people”. However, as hard as I try to imagine, I can not fathom Hillary Clinton standing in a line anywhere, waiting for service. Even going into a fast food restaurant, my guess is that she always receives table service. It is the nature of the beast.