We see advertisements for food almost every single time they go to commercials on TV. Commercials are the number one way for getting products out their for people to see. Anything from billboards, TV's newspapers, Magazines, sides of taxi's, buses, and trains will be advertising a delicious delicacy. Just take a look around very closely. I bet you can't go a day without seeing or hearing an ad about food.
Now the creators of these commercials for TV's or pictures for newspapers or magazines have a very important job. That is to make whatever they are advertising look delicious, and mouth watering. So they will spend countless hours doing whatever it takes to make that burger look very appetizing.
Going with what i said though is a reason why obesity is a major problem in the world today. You take a look around and you see ads for sandwiches, soda's, pizza, candy, fries, chocolate, anything that is technically unhealthy for us. How often do you see ads for fruits and veggies? not as often as subway does ads for foot-longs, or McDonald's is doing another commercial for Big-Macs. People see a commercial for lets say a steak at Outback, They will then most likely be craving a steak from Outback. The creators of these ads for foods will do anything to make the viewers start craving their items. It's their job, that's what they are suppose to do.