The VisualElement is hidden. Hidden VisualElements will take up space in their parent layout if their positionType is set to PositionType.Relative. Use the DisplayStyle style property to both hide and remove a VisualElement from the parent VisualElement layout. Note, this is the enum value used when setting styles via VisualElement.style.visibility. In C#, you can just use VisualElement.visible = false.