Pain!!!
Lady Amy wears nice high-heeled shoes with thin and spickey heels, best for treaten her slave with them.
She orders him with soft kicks to the floor, then she steps on everything of him.
Beginning with steps on his feet she continues on his legs and soon she lands on his stomach, here is a good place for stiching her heels deep in his worthless flesh.
She orders him to turn around and tramples his back, here is the use of heels like this extremly painful.... Amy's style!
To the end she "paints" another picture with her heel in the belly-flesh.