Attached file is the relevant pose, a WIP. ;)
Let's discuss sidesaddle; a position wherein a female partner straddles a male lover with both legs over to the side and pressed together, as though riding a horse sidesaddle... hence the name.
I have always found something so erotic about the press of thighs and legs together completely down to the ankles. There is something pavlovian, certainly- the knowledge of knowing how pressed tight one is, a woman's pearl in the ideal position for stimulation, muscles clenched tight around a phallus. I find more intensity of pleasure when my legs are pressed together- there is more blood flow, more active pressure and pleasure when clenching like that. And of course, depending on which side I'm taken, my G spot in particular has a side preference. (Which is Very priviledged information. ;) )
But there's also an aesthetic attraction; it's beautiful to see thighs pressed together all the way down to the heels. I have Something of a shoe thing, and those heels are Sexy. It feels Sexual to be in them, full of power and feminine sensuality, commanding the desire of a lover.
I favour it in both visual media, and in personal practice. There is a common link between these things and enjoyment of smut, I've found. ;)