When you add a drawing element to your scene, a folder is added to the scene directory. This folder is named the same way as the drawing element and is in fact, linked to the drawing element. Its purpose is to contain all the drawings related to this element (layer, column). For example, in cut-out animation, a character can have many heads available. All of the head drawings will be contained in this folder, even if they are not exposed in the Timeline or the Xsheet view.
Drawings are exposed in cells/frames and linked to the drawings saved in the layer's directory. When you remove a drawing from a cell/frame, it is not displayed, but still exists in the directory.
When you create a drawing cycle, all of the repeated drawings are linked to the original files. This means that when you modify, repaint, or correct a drawing named “1,” all exposures of drawing “1” are updated simultaneously. In order to modify a drawing independently from its other exposures, you must duplicate the drawing.
You can add drawing elements from the Timeline view, Xsheet view, and the Scene menu.