But what if next to the ad was a picture of the delicious-looking burger, and you had some money on you? Which of the two situations are you more likely to buy the burger?
If you mention scenario 2, then congratulations, you are not a vegan.
And the reason why the second scenario works is because of priming. Exposure to a stimulus will influence how you react to another.
In our case above, you were exposed to the stimulus, which was the image of a delicious burger through the ad, which caused you to react with desire and ultimately, getting yourself that burg.