This one was an interesting challenge, because it took me a while to figure out why I had my initial arousal response when I first glimpsed it. I like blue in general (in fact it's really my favorite color for just about everything except lingerie) but blue lace panties aren't a big turn on for me in and of themselves. Something about the combination of the chocolates and the slightly contorted arrangement of the female stomach, hips, and thighs, in combination with the lace, though, was strongly arresting.
There also is no obvious BDSM element in the photo (no leather, no chains). Indeed I think that it's actually the subtlety of the placement of the chocolate casually on either side of the panties, some on the stomach, some on the thigh, that constitutes the essential hotness here, which I then tried to elaborate in the little story: the implication that comes through to me is of a Master who uses his submissive's body to set off his chocolates, rather than using his chocolates to set off his submissive's body. That is, the girl is being treated like a plate, and her panties like a doily.
Some might wonder "Why the spanking?" since I've just arguned that the essential hotness is elsewhere, in the relationship between the panties and the chocolate. My answer is really simply that for something to be really, really hot for me, it just always has to involve a spanking. As most spankos would agree, I think, for us spanking is a kind of sine qua non of eroticism. If my character Anna were going to be as aroused as necessary for the display I envisaged to be complete, she was going to have to be spanked.