After a few minutes of burning, a tortilla will start to warp.  Bubbles will appear, the shape will get distorted.  And as the tortilla cooks, it gets crisp.  So those bubbles and distortions will become fixed and immoveable.  You can't just get out the iron and smooth them out, daddy.  No way, they are here to stay.

So this is what the tortilla looked like from the front.  Pretty good, right?

But let's take a look at it from some different angles.