Children properties
The containers and layers are objects with children, and share children-based properties.
The Children properties are not part of the Phaser API, they are used only by the editor, in design-time.
The Allow Picking Children In Scene property allows picking a child in the scene. If it is disable, you cannot pick a child by clicking in the scene. This is useful if you want to manipulate the parent container (or layer) and children as a single object.
The Show Children In Outline parameter is similar. It allows showing the container or layer children in the Outline view.