Show or hide an object on the artboard
The column under Hide all/Show all indicates the visibility of an object on the artboard. When the eye button is visible in the row that corresponds to an object, the object and all its child elements are visible on the artboard.
Hide/Show applies only to the view of your object on the artboard in Expression Blend. Hide/Show does not affect the visibility of your object when you run your application. For more information, see Show or hide an object in your application.
You can modify an object on the artboard when it is hidden, but you will not be able to see your changes reflected on the artboard until the object is visible again.