A woman is signaling is to traffic, as seen from behind.
Someone with their back to the camera is motioning to cars.
A woman would also be a " someone ". If she is seen from behind, her back is to the camera.
exists e1 e2 p1 x1 x2 x3.(as(p1,e2) & from(e2,x3) & n_behind(x3) & Theme(e2,x1) & v_see(e2) & exists x4.(to(x1,x4) & n_traffic(x4)) & Actor(e1,x2) & v_signal(e1) & (x1 = x2) & n_woman(x1))
exists e1 x1 x2 x3 x4.(n_camera(x3) & to(e1,x4) & n_car(x4) & Actor(e1,x1) & v_motion(e1) & to(x1,x3) & with(x1,x2) & n_back(x2) & of(x2,x1) & n_thing(x1) & n_person(x1))