Doll Transformation is one of the major future spells since Episode 4: I Can't Bear A Goodbye.
When being a doll
Once an angel becomes a doll for any reasons, they cannot feel the needs when they are like in human form, such as of being hungry, tired, they don't have to use the restroom, or anything else that humans suffer in life. They don't have to do anything. The only thing they can do is listen to conversations of anything of sort in the room their in.
Once they return back to human form, they feel the same before coming into a doll, like nothing changed.