The Repeat Images feature
By default, all the images in the exposure cells are the same, by definition, they are only a "link" to the head image.
However, this feature allows you to use the previous images of an instance, in its exposure cells.
This option is really useful, in particular when a character stops moving, but whose lines still shake (a graphical aspect very appreciated by traditional animators).
This is made possible by the Repeat Images Value option available in the Timeline's contextual menu. That value is applied on the wished exposure cell (you cannot use that value on the instance's head).
Let's see how to use this feature. Say we want to repeat images on the last instance of the animation pictured below. We want this repetition to start on the last instance's third exposure cell:
The value in the field below represents how many previous images will be repeated in the exposure cells of the last instance, from the exposure cell of your choice (in the present case: the third one). Ìn our example, we want to repeat the previous exposure cells, the instance's head and the three previous instances, so a total of 12 images:
The third exposure cell contains a blue circle, the sixth one will contain a red rectangle... and this repetition will loop as long as the instance will have exposure cells.
The Repeat Images Value set to 12 images
You can also set different behaviors than Repeat, such as Ping-Pong and Random.