During Step 4 of a grapple maneuver (To maintain a grapple, you move into opponent's space), how would that movement be managed if the creature moving into the opponent space is larger that the target (for example an ogre grappling an elf and moving into the elf's space as a result of a successful grapple check)?
It is indicated in the rules that when a larger creature occupies a smaller character's space, only the larger space remains on the grid and the smaller creature is considered now occupying the same space as the larger one (so the elf is now occupying a 2x2 square) and anyone that can reach that space can now attack the elf.
But how is the larger creature space placed on the battle grid over the smaller one? Does the attacker choose? Does the defender? Is it random? The closest point?
I have not seen anything in the rules stating this. Please indicate if your answer is based on the rules as written, as this is what I am looking for. I tend to assume that if there is no ruling, it is whatever the attacker chooses since it is done during his turn and it is during his action.