ドーナツの穴って何であるんだろう？

2girls,(blond hair:1.2),short hair,bob hair,(blue eyes:1.1),(hair bow:1.4),(red bow:1.4),black hair,short hair,brown eyes,curious expression,puzzled look,wondering face,small chest,loli,casual clothing,white dress,pink cardigan,blue overalls,striped shirt,white socks,colorful shoes,(donut:1.3),(donut hole:1.4),glazed donut,chocolate frosting,rainbow sprinkles,sitting at table,leaning forward,pointing at donut,heads close together,examining closely,cafe interior,wooden table,comfortable chairs,warm lighting,cozy atmosphere,innocent pose,legs swinging,hands on table,tilted heads,contemplative moment,(masterpiece:1.2),(best quality:1.2),(very aesthetic:1.1),(absurdres:1.1),