This property allows you to specify the image to display within the layout item's caption by its index in an image collection.
The ImageIndex property specifies the index of the required image in a collection of images. In a LayoutControl, the source of images is specified by the LayoutControl.Images property. In a LayoutView (Grid Control), the source of images is specified by the ColumnView.Images property.
It's also possible to explicitly assign an image to the item using the Image property. If images are specified via both the ImageIndex and Image properties, the image assigned to the Image property will be used.