Jane has her slave in a high bench, which allowed her to sit like on a saddle with the feet of the ground,
Now his face is her saddle, she mounts him and sits with all her weight on the poor face.
She wants to train his breathholding abiltiy with longer sitting periods, but he struggles, because lack of air; he cannot hold his breath long enough.
So she moves on his throat, crushes his windpipe under her, maybe he learns.
But he seems to enjoy this to much, so she moves again on the face and crushes the nosee with the hard jeans-ass.