So i'm assuming they basically listed population size in one column and square footage in the other and sorted them each, then placed the population name on land spot?

That is what it looks like. It is strange that the US and Brazil didn't move.

That's grand.

If it was random, you'd expect one country to stay in the same place.  But because bigger countries tend to have bigger populations, there's a decent chance that two or three countries would stay in the same place.

Right, here's a good one - can you rank countries by land volume instead of land area?  Tenerife is 2,000 square kilometres, but 3km tall.  Saaremaa is over 2,500 square kilometres, but only 50m tall.  So Tenerife has a bigger volume.