Meaning . . . what, exactly?

Corn syrup makes an item outdoor good. Which outdoor? The Golan Heights are outdoors. Babi Yar was ourdoors. The entirely of the battle of Gettysburg was conducted outdoors. In all my years of eating flapjacks, I've never wondered if they could be better if they were made outdoors. The possibility that pancakes could have some undefinable yet instantly recognizable quality if only they were prepared outside the confines of a man-made structure never occured to me.

As for the recipe - it’s just a patently obvious attempt to double syrup consumption.

Just a guess, but: the phrase “pour-on” smacks of industry lingo. As in: well, the boys have run the numbers through the Univac, and pour-on sales are projected to go nix-wise in the next two quarters.