Picture of a hotdog vendor in the street.
A waiter stands in a restaurant.
The first sentence is describing what is seen in a picture, where as the second sentence does not mention a picture. A hotdog vendor is not a waiter. They are in the street and not in a restaurant.
exists x1 x2 x3 x4.(n_street(x4) & a_topic(x1) & of(x1,x2) & in(x2,x4) & n_vendor(x2) & of(x2,x3) & n_hotdog(x3) & n_picture(x1))
exists e1 x1 x2.(in(e1,x2) & n_restaurant(x2) & Actor(e1,x1) & v_stand(e1) & n_waiter(x1))