A snapshot stores the state of your work at an arbitrary point in time, much like a freeze frame.
In contrast to reverting edits step-by-step using the History panel, snapshots let you instantly restore your work to an explicitly defined stage.
You might do this in advance of carrying out a sequence of complex operations to allow yourself to step back to a specific point in time if things don't go to plan.
Multiple snapshots can be created. So, if you're experimenting with different design ideas, you can also create a different snapshot for each one to help you decide which idea you prefer, all while working in a single document.
If needed, you can create a new document from a snapshot.
The Snapshots panel is available in the Photo Persona and the Develop Persona.
In the Develop Persona and Photo Persona, the panel is collapsed in the right studio and hidden by default, respectively. For the latter, the panel can be displayed via Window menu.
In the Photo Persona, it can be used in conjunction with the Undo Brush Tool to paint back to a chosen snapshot.
A snapshot layer is created from a predefined project snapshot and is added to your project as a single, flattened pixel layer.
From the Layer menu, select a snapshot from the New Layer from Snapshot submenu.
The snapshot layer is added above the current layer (or at the top of the Layers panel if no layer is selected).