My client had this idea for a campaign where the product would be part of the food itself. They supplied the layouts and I created the images using photography and Photoshop. The shot of the Pepto bottle was created separately, then printed and pasted to a board at different sizes, sort of a real world sprite.
Then that printout was inserted into the food shots, to add the correct color cast and shadows to the rest of the image. Then later, that sprite was replaced in photoshop with the original product shot.