A boy is performing a skateboarding trick with trees in the background.
a kid is doing skateboard tricks for his friends
There is no mention of who the boy is performing for so it can not be inferred that it is for his friends.
exists e2 e1 x1 x2 x3 x4.(n_background(x4) & Theme(e2,x2) & Actor(e2,x1) & v_perform(e2) & with(x2,x3) & in(x3,x4) & n_tree(x3) & n_trick(x2) & Actor(e1,x2) & v_skateboard(e1) & n_boy(x1))
exists e1 x1 x2 x3 x4.(for(e1,x4) & n_friend(x4) & of(x4,x1) & n_male(x1) & Theme(e1,x2) & Actor(e1,x1) & v_do(e1) & n_trick(x2) & of(x2,x3) & n_skateboard(x3) & n_kid(x1))