A person holding a dog while they eat.
The dog is Paul McCartney.
The subjects are different. The subject of the first sentence is a person and the subject of the second sentence is the dog.
exists e1 p1 x1 x2 x3.(a_topic(x1) & exists e2.(Actor(e2,x1) & v_eat(e2)) & n_thing(x1) & while(e1,p1) & Theme(e1,x3) & Actor(e1,x2) & v_hold(e1) & n_dog(x3) & (x1 = x2) & n_person(x1))
exists p1 x1 x2 x3.(ne_per_mccartney(x2) & (x2 = x3) & ne_per_paul(x3) & n_dog(x1) & (x1 = x2))