Toaster ovens use 3 main sources of heat. This includes radiant heat (from the elements and metal walls), warm circulating air (within the toaster oven), and conduction (which comes from the baking pan or dish).
When reheating pizza in a toaster oven, the temperature is important. You don’t want it too high or you’ll end up with burnt pizza. The wrong temperature can lead to a rock-solid crust, cheese that is overcooked, or pizza that is soggy.