The applet manipulates the cow image as follows:

Use the view Control to pick which transformation to use, and which type of projection to use.

Drag a line across the image. This vector will be used to tranform the image:

Translation : translates in the vector's direction

Rotation: rotates around the vector an angle proportional to its length

Scale: scales the image down to fit inside the bounding box of the vector

Shear: shears the image where the shear params k12 = x and k13 = k23 = y.

Note: the transforms are applied to the model space (not the gloabl one)