This took place at windy city's wing chun 5th annual seminar. I take no credit at all, as my Sifu just showed some superior blocking skills. If you know what to look for you can see tons of different concepts being applied. The 1st thing to notice is that a skilled practioner really just blocks the majority of the time, the unskilled, tries to cover that up by simply blizting the attack. Its very common in the wing chun world for many to do that.
Also, what how blocks come about, its not done by the hand but by the body. You can visually see this since sifu's center stays consistent throughout, and simply turns in conjunction with the amount of force, while the hands don't chase out which is a common no no in wing chun. Let the attacks come to your house, and the closer they are the safer it is for you. All to often, people will shoot out their hands trying to reach out to block.
Blocking is a simple concept but difficult to do, know the person's centerline, have your triangle constantly point to that indivudals center line, and go with the force. While there are many more concepts involved these are the general three which one must follow to develop superior blocking skills.
Finally in some glimpses you see freezing out motions, where you can literally lock out your opponents motions, by simply holding your structure and techincally freezing his hand motion. All to often wing chun is confused with the concept of sticky hands. Sticky hands is not about sticking to people, its making people stick to you. Out in the street, people will not do sticky hands in a real fight, what your developing is the ability so that people will stick to your hands. In a simple concept imagine your hands as blades, if you position your blades in the right angle, whatever touches it will cut into it, thus forcing that individual to stick.
Anyway, if you want to get good in wing chun, practice blocking more then attacking. If you can block anything thrown at you, you can then attack at will.