Both resisting and yielding are all bad solutions. The reason is you are reacting as your opponent wants you to react.
There are two components to the reaction: spatial and temporal. You (KFW) are only thinking about spatial: going where the opponent wants. However, if we consider the temporal component, a good tai chi artist goes where the opponent wants (sticking), but
sooner than the opponent wants him to (sensing & anticipating), closing the distance and staying "in the game", maintaining options. Actually, by staying close, black would
not be going where white wants: white depends on a specific orientation (distance and angle), and black need not oblige.
One follows (yield, if you will) until your opponent 'runs out' of his own. Change must occur. The video you posted is not of a very skilled player as there is too much of a gap between opponents.
Yes -- the black shirt is not sensing or sticking in order to anticipate, but instead is waiting for white shirt to define the interaction.
One 'sticks' closer so that one is able to 'read' the opponent. Think of this: You do NOT let a kicker kick - you close the gap, not allowing his/her room to launch an attack.
Yes. A good Tai chi artist would be aware enough to sense that the pull was coming (before white shirt reached full extension) and move in to push white shirt, disrupt him, or strike. Black shirt is very slow: why is he standing there, not even turning as white shirt moves around him before reaching full extension? He should have turned
with white shirt and closed the gap, never allowing white to get beside/behind him, and should have moved
with white shirt, never allowing him to get that far away.
Of course, another option for black would be to spiral his arm to release white's grip.