The boy in red is adding his message to many others.
A kid is writing a message on a banner.
Boy can be used to describe any age male and adding a message to others doesn't have to be on a banner.
exists e1 x1 x2 x3 x4.(n_boy(x1) & to(e1,x4) & -(x4 = x2) & n_person(x2) & n_person(x4) & n_quantity(x4) & Theme(e1,x3) & Actor(e1,x1) & v_add(e1) & n_message(x3) & of(x3,x2) & n_male(x2) & in(x1,x2) & n_red(x2))
exists e1 x1 x2 x3.(Theme(e1,x2) & Actor(e1,x1) & v_write(e1) & on(x2,x3) & n_banner(x3) & n_message(x2) & n_kid(x1))