Unifying Layer Properties (PSE 15+)

And what if you need to modify the appearance of the entire animation?

Solution 1: To apply the current layer properties to all the frames, run "Match Layer across Frames" command (fig. 1/1) and, in the dialog that opens, define which exactly properties to match (fig. 1/2).

Solution 2: Run "Select All Frames" command (fig. 2) and then hide, show, move layers, or edit layer styles.

Solution 3: By default, modifying the first frame of the animation affects all the other frames as well. So, you can just select the Frame 1 (fig. 3) and then make the required changes.

If you want to edit the first frame without altering the follow-up frames, uncheck "Propagate Frame 1" option (fig. 4).