enforce the right texture sizes when loading tile data and make the tile manager a little less verbose
That is what it does, but it also adds the beginnings of the wall (as in the vertical counter-parts to floor tiles) book-keeping code (no renderer code yet) to the Floor class. What that means is more detailed are functions for getting vertex data (non-functional), calculating a wall state hash and references to the yet almost empty WallManager.
The wisdom of this is more than questionable and it will in all likelihood get moved elsewhere.