The vision offered is quite surrealist, more like a painting.
The girls and her withe clothes look like not to be in the stair. Like a ghost, too bright for the place, she catches our eyes and surprises us as she is surprised herself.
Her pose and expression makes us reflecting on this photo, thinking about it, letting us in reflection and mystery.
I hope you let the model breath after this. The model is cute and her pose sexy without beeing nasty.
The cloth add to the mystery of the situation.
I will not critique the technique as I see no default in this "Chef d'oeuvre."