My first observation was also the feet ! Seemed to be excessively sadistic to burn the women's feet to a crisp. There is not a lot of point to the rest of it as the pain from her feet burning like that would likely cause the women to pass out.
Porn of women being racked is, naturally, rare & hard to find. So, it's nice that artists are making computer generated videos for us, now. I few "observations" if I may. The victim would be screaming, at the top of her lungs, even before the rack was tightened. Due to the fire below her feet. This, I'm afraid, would soon burn her feet, so they would slip through the stocks. And what about the man whipping her? Wouldn't he have a vertical erection? Maybe it could rise, as the girl is being stretched?