About the Animation Cels Palette
You can refer to other cels (layers) or image files while drawing animation cels. Set the cel to be drawn as the [Edited cel], load the reference cels and register them to a [Light table specific to cel] or [Common light table for canvas].
Cels and images registered to a [Light table specific to cel] or [Common light table for canvas] are called light table layers.
Light table layers can be altered according to the content being drawn. You can move the layers, transform them or change the layer color. Changes to light table layers are not applied to the original cel or image.