Clicking the "Process all images"-button starts the batch-process. For this purpose, a sheet is displayed which indicates the progress of the batch-process.
The batch-process can be aborted at any time. There is usually a small delay in stopping the batch-process because the current image being processed will be finished before the entire process is being stopped.
When all images have been processed, the OK-button in the batch-process sheet is released. In addition, a signal sounds when processing is completed.
To start the batch-process you can also use the keyboard shortcut CMD+Enter instead of pressing the button.