te can't. In most quizzes, the Prizes immagini are the same, because they are generated da Fanpop. See the default prize lista link But, on some quiz like the Twilight o the Harry Potter quiz, the prizes immagini are different because the F4 made those custom prize sets.
But, if te want to know più about this see link articolo (there may be something in there about changing the quiz prizes immagini ;D).
