False Advertising. Where is the line between truth and a law suit?

Advertisements should entice you to buy a product. But they should not to lie to you. The question, when it comes to food styling, is where is the line between the truth and a lie? Is a photo of a burger true if it has all the ingredients doubled over at the front, but it is empty at the back? Imagine a photo of a glass jar of lollies, that when pictured from the front