A man in a brown leather jacket observes a portrait.
A man is looking at something
Observes is a synonym of look and a portrait is an object, so the man by looking at a portrait he's observing something.
exists e1 s1 x1 x2 x3 x4.(Theme(e1,x4) & Actor(e1,x1) & v_observe(e1) & n_portrait(x4) & in(x1,x2) & n_jacket(x2) & of(x2,x3) & n_leather(x3) & a_brown(s1) & Theme(s1,x2) & n_man(x1))
exists e1 x1 x2.(at(e1,x2) & n_thing(x2) & Actor(e1,x1) & v_look(e1) & n_man(x1))