A girl wearing a pink shirt lays on the green grass and looks up.
A girl, is lying on green grass.
The fact that the girl is lying on the grass means that she did not lay there; the word lay implies that she is an object that was placed there, but the word lying implies that she placed herself there.
exists e1 e2 e3 s1 s2 s3 s4 x1 x2 x3 x4 x5 x6 x7 x8.(n_grass(x5) & a_green(s2) & Theme(s2,x5) & a_topic(x1) & Theme(e3,x6) & Actor(e3,x2) & v_wear(e3) & a_up(s4) & Manner(e2,s4) & Actor(e2,x8) & v_look(e2) & (x6 = x8) & n_lay(x6) & of(x6,x7) & n_shirt(x7) & a_pink(s3) & Theme(s3,x6) & Theme(e1,x3) & Actor(e1,x2) & v_wear(e1) & on(x3,x5) & n_lay(x3) & of(x3,x4) & n_shirt(x4) & a_pink(s1) & Theme(s1,x3) & (x1 = x2) & n_girl(x1))
exists e1 s1 x1 x2.(on(e1,x2) & n_grass(x2) & a_green(s1) & Theme(s1,x2) & Actor(e1,x1) & v_lie(e1) & n_girl(x1))