public ObjectProperty<Image> iconProperty() {
        if (null == icon) {
            icon = new ObjectPropertyBase<Image>(_icon) {
                @Override protected void invalidated() { fireSectionEvent(UPDATE_EVENT); }
                @Override public Object getBean() { return Section.this; }
                @Override public String getName() { return "icon"; }
            };
        }
        return icon;
    }
Defines an image for the section.
In some skins the image will be drawn (e.g. SimpleSkin)
@param IMAGE
src/main/java/eu/hansolo/tilesfx/Section.java