How do photographs contribute to the effective communication of an advertisement's message?

pick two photos that have been used for advertising purposes, and use compare and contrast style of essay but compare the pictures seperately. to personal views (what i think and what is the actual reason) not to each other. use a source online and from these books i got from my library ; The Photography Reader (Liz wells, 770.1W) Between The Eyes (David Levi Strauss, 7701s) Why Art Photography (Lucy Soutter, 770,1s) Classic Essays on Photography (Alan Trachtenber, 770.11 PLACE THIS ORDER OR A SIMILAR ORDER WITH US TODAY AND GET AN AMAZING DISCOUNT :)