Four boys pose for the camera.
Four boys are posing.
Posing for the camera means the boys are posing.
exists e1 x1 x2.(n_camera(x2) & for(e1,x2) & Actor(e1,x1) & v_pose(e1) & n_boy(x1) & card_eq_4(x1))
exists e1 x1.(Actor(e1,x1) & v_pose(e1) & n_boy(x1) & card_eq_4(x1))