I want to skew the dynamically called image

Well skewing can be done with the Matrix class in Flash. There is a great tutorial here:

http://www.senocular.com/flash/tutorials/transformmatrix/

However that is not skewing that is perspective (or mock perspective) and I have not idea how it is done. In the past folks were able to break up images into multiple triangles and the scale, skew, transform those to make the whole look like perspective. That might be going on here, but usually if you change the player quality to low you can see a bit of the edges of the triangles – which I don't.

Perhaps it is something with the Bitmap class.

Whatever it is it most likely involves a lot of math. I would like to know myself.