Explanations of shockwave for the common folks (youtube videos, googling) all tend to focus on successive sound waves generated by the air craft traveling outward in circles (sphere).
That to me, only explains why the boundary of a sockwave is a straight line (cone). It doesn't really explain:
 why the sudden pressure or velocity change of the air after the boundary.
 I can't use that to explain the shockwave on wing surface.
I have a feeling that shockwave on wing is not so much related to noises made by the plane, but it is related to solid cutting into liquid forcing the liquid into some behaviors, that in turn acts back onto the surface.
What I think I understand: sound wave being a planar wave of pressure, bernoulli effect and lift.
so on those foundations, could some one explain how is sockwave formed, and why is it parpendicular to the wing surface.
I prefer microscopic understandings, as in layers of particles, starting from the layer touching the surface of the wing and explain our way layer by layer away from the surface.