Accessor of the slot image of the gtk-button class.
The generic function gtk-button-image gets the widget that is currently set as the image of button. This may have been explicitly set by the generic function (setf gtk-button-image) or constructed by the function gtk-button-new-from-stock.
The generic function (setf gtk-button-image) sets the image of button to the given widget. Note that it depends on the gtk-button-images setting whether the image will be displayed or not, you do not have to call the function gtk-widget-show on image yourself.