In action, it looks like "just a punch". That was a critique some made of WSL's fights. He "just punched and kicked". But that's what VT is!
It's subtle, not a technique. It is not in reference to what an opponent is doing and how I use my elbow or contort my arm to wedge them out this way or that depending on what they do. Without understanding overall strategy and tactics, you will be seeing "just a punch".
It's strategic. It's trained throughout the dummy form, which many take as techniques against an opponent. They see the arms as representing a human or punches. Rather it's a tool to refine our own actions within the limitations of our own structure.
Many are obsessed with occupying the center. So they hold their man/wu on the center and move straight forward with it, aiming to wedge things out. This breaks things into "4 gates" and they are forced to use one hand to defend one of these gates while the other hand punches. Inefficient. Or they are forced to make a detour and cut back in on an incoming attack because they are stuck on the center. Indirect.
It's more about spatial domination that doesn't require stubbornly occupying the center. The correct position and path of wu-sau is taught in CK where it forms a punching unit with bong-sau (aka kwan-sau). But people are too focused on application ideas that they entirely miss the strategic ones.
Rather than 4 gates, I want to cut that in half in such a way that I only need to use one arm with dual functions in direct attack, and two such arms in rotation to sustain an unthinking assault regardless what the opponent does. I don't want to defend with techniques at the mercy of my opponent. I will get set up. I want to protect space while attacking so that I need not think and decide which hand to use where. I want to impose upon the opponent, as guy b. says. Take their space and facing away, limiting their options for response.
I also don't want to let them turn me, as some lineages do. Overturning on one's own is hard enough not to do in the heat of a fight. Training against this begins in CK, where most focus on elbow strikes and other application ideas. We turn the opponent or if the opponent turns themselves, we let them overshoot, taking advantage of the mistake, and taking whichever side they expose. The opponent shows us how to hit them.
But in action, and to the untrained eye, you will only see "just a punch".