LevelLayoutLoad2

So my question for this is about the routine "LevelLayoutLoad2" in s1.asm. In the comment section above it, it says that it runs twice, once for level and again for background. I completely understand that it does, but I want to know what command tells it to run again. The only thing that I see repeating is at the bottom where it repeats the last few lines for each row the level has, but not the entire thing.