There are two types of operations that can be performed on an image in the editor - Tools and Commands. You can read more about the difference between the two and how they work here.
In a nut shell, tools are able to generate a live preview of the effect you are applying on the image with different parameters. When you hit enter, the tool is committed, i.e. a command with the parameters from its SettingsUI is executed and registered in the undo/redo stack. Then, the effect of this command can be reversed and reapplied on undo/redo.
I hope this helps.
the Telerik team
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