First, and most importantly, great food photography should make you feel hungry! Advertising companies want to make money off of their product, so, the food has to look delicious to the viewer. The chocolate dripping down a cake should make you want to reach in, grab a fork, and take a bite. In order to bring out the biggest appetite appeal, food has to be carefully styled and lit. The way in which we prepare food to eat for dinner is completely different from the food we prepare for a photo shoot. Meats often have to be under-cooked to bring out their fresh/juicy appeal, vegetables are often flash cooked for a minute, and then blanched to bring out their brightest color. Salads are often piled higher to make them look full of life. A great food stylist will have the knowledge and experience to make food look delicious for the camera.
Secondly, great food photography can also evoke a feeling or past-time. Perhaps you see an image of lemonade in a pitcher on a wood table next to a swing-set and this instantly reminds you of your favorite past-time (of drinking lemonade and playing on a swing-set). Although evoking a feeling or past-time is not necessary, if your images can impact someone on a personal level, that can be very powerful.
If you're looking for a Southern California Food Photographer who can bring out appetite appeal while also helping to evoke a feeling or emotion, turn to Rob Stathem Photography.