Those symbols are generally to indicate items that are available for snack credits. They don't seem to have symbols next to the entrees.
With a CS credit, at any participating restaurant you are entitled to any one entree or any one combo meal, one dessert, and one non-alcoholic beverage. For breakfast, substitute a second beverage for the dessert. There are very, very few restrictions and those mostly concern desserts - at some CS only certain desserts are eligible, and an extreme few don't have desserts at all.