It goes without saying that the advertised version is the one shown inset at the bottom right. Here in Japan there is a Japanese burger chain called "Mos Burger" whose burgers actually turn out the same as they look on their menus. I don't think it is too much to ask for.
Usually, when a Japanese company wants to indirectly admit that a pictured product may differ from the actual one, they add a disclaimer such as "写真はイメージです。" ("Picture for illustrative purposes only.") McDonald's does no such thing.
drormiler, who commented below, put me on to the Breakfast Scene from the movie "Falling Down" in which the main character also deals with this problem: www.youtube.com/watch?v=-eREiQhBDIk