An effect often applied at the compositing stage is the texture overlays. With this effect, you can replace solid colours in your character with tiled-on bitmap textures, or replace their solid outlines with textured, natural-looking pencil lines.
To enhance this effect, you may want the texture override to be animated. The texture override can be composed of multiple drawings, which can be looped through as the scene plays out. You may want these texture drawings to change at a constant pace, or only when the character's action is fast enough to warrant it, to give it a more organic or stylized look.
This is where the Exposure Fill Using Render Change command comes in handy. This functionality allows you to automatically fill the texture layer's column with different drawing exposures relative to how intense the action is in the rendered image. You can define how much action is enough to warrant a drawing swap, letting the textures sit still when the character is inert but making them animated when they move.
The Exposure Fill Using Render Change command can be applied on any drawing layer, but the most common case where this feature will be when a layer containing texture drawings is being used by a Colour-Override through its texture port to replace one of a character's colours with a texture. The drawing layer containing the texture drawings should have at least a few different texture drawings for the Exposure Fill Using Render Change command to be able to swap between them. For more information on this approach, see Overriding a Colour with a Texture Sequence.