This picture is using the rule of thirds and the main subject takes up 2 of the three thirds with the subject crossing 3 of the 4 intersections.
Here we have a pizza pie that does not follow the rule of thirds. the pizza is plainly centered, making and uninteresting composition. The person may have broken the rule just to have a good view of a pizza.
Here we have another pizza that does follow the rule of thirds. The slice of pizza being lifted happens at a point of interest and the rest of the pizza rests in the lower two thirds of the photo. This pizza looks a lot more appetizing.