I think it has to be the white robe. Or, perhaps more properly, the contrast presented by the white robe, to the lash, and the hand, and the apparently mystic tattoos on the muscular masculine forearm.
Her eyes are closed, it seems to me, because she doesn't want to see the frightening appearance of the whip with which she must be chastised--but also, I think, because she is living inside herself at this moment. I imagine her as reminding herself, in the face of the terrifying sight of the whip and the strong hand that will wield it, that she has come there because she needs the whip, and the hand, and the dominant mental force behind it.
For that reason, I also imagine her as being initiated into an unnamed mystical order, for the white robe is above all, everywhere, the robe of the innocent who will be brought into a sacred mystery. For me, there is no mystery more sacred than that of submission; my Jeanne, in this little story, yearns to experience an ineffable erotic pleasure of which she has dreamt.
Because that pleasure, for me, arises in the surrender to the will of a masculine other, Jeanne's husband Blaise will borrow the power of the Master of the Lash as, for me, a dominant man borrows the power of masculinity itself. For me, there are no alpha males: there is only play; a dominant who plays his part well will seem like the Master of the Lash, but he will be, for example, my loving husband.
That sacred, higher, dominant power appears in this photo in the way the strong hand holds both the lash and its handle both delicately and with total assurance. The curl of it into his fingers, and the way its end dangles through the loop thus also constitutes its own mystic sigil, and gives the wielder the authority to mark Jeanne according to the fashion known to that power alone.
(If you like these stories, try the Companion to EXPLORATIONS!)
(Caroline's Rocking Horse [Mf, ageplay, anal] and The Count's Discipline [medieval, spanking, anal] are available at Amazon!)