By default, the Visible property is True, so the picture is visible on the layer's background. Use the Name / Value property to specify a picture to be displayed on the layer's background. For instance, you can use Visible property on False, to prevent showing the picture on the layer's background. The Selectable property specifies whether the picture on the layer's background is selectable. The Visible property of the Background object, affects all the pictures / colors being shown on the layer's background. 

The picture is displayed on the layer's background if both of the following:

• Visible property is True
• Name / Value property points to a valid picture

are accomplished.