Thread:Omega64/@comment-4503935-20190703001710/@comment-10330822-20190829005532

My guess is that it is part of Gaara's will. After all, it didn't start happening until Rasa made it clear that it was Karura's will that caused the sand to protect Gaara, not Shukaku's. So, my guess would be that once Gaara identified his mother's will in the sand, he started subconsciously forming his techniques into visages of her.