Each brand is trying to find a way to get a leg up on the competition in a tight market space. The above picture is what I found on my last grocery run. What caught my eye was the asterisk next to the non-GMO popcorn claim. My guess was the ingredients list would include soybean, canola, or corn oil.
The temperature for broiling in an oven is 260 degrees Celsius or  500 degrees Fahrenheit. Medium heat is about 177 degrees Celsius or  350 degrees Fahrenheit.
The smoke from broiling is consumed as it is drawn over a rod-type broiler element. Set the oven thermostat at BROIL for a full broil or at any desired setting between BROIL and 350 degrees F for variable broiling (see chart).