Depends if lager yeast or ale yeast are used.
Actually this isn't as important as you think. You can make ale with a lager yeast and lager with an ale yeast, it will just take longer and probably won't taste right. The temperature, however, is very important, because different yeasts prefer different temperatures. As it was explained to me, if the wrong temperature for the yeast is chosen either they won't multiply quickly enough and bacteria will overwhelm them, or they will start to consume the wrong sugars and produce bad things like fusel alcohols. (Random trivia: the name "fusel" comes from the German word for a bad brew.)
Grandparent's post is accurate because certain simple sugars settle to either the top or bottom of a fermentation vessel. The yeasts will tend to congregate where the food is, and the food depends on the temperature. Ales multiply quickly and ferment in the top of the vessel, while lagers go nuts at the bottom. Interestingly enough, most major beers nowadays labeled "lager" are actually ales. My guess is that since the sugars are completely homogeneous in space, assuming you can keep the bacteria out you might wind up with a very smooth beer as everything ferments evenly... but it will take longer to brew. Or you might end up with a completely awful beer.
To answer the GP's question, I guess this means that if it ferments further toward the enemy's gate, it's a lager?