On the Gold plan, you get one less vegetable, and your protein serving sizes decrease by about 2 ounces (6oz chicken, 4oz beef, 2 eggs, 1/2 cup cottage cheese, etc.). I think there are some differences in the carb cravers, as well.
WELCOME TO LAWL! POP means "perfect on plan" so these are the days that you measured and weighed all the correct quantities of food. And you ate no more, and no less than what you are supposed to according to your plan.