After clicking the BATCH button you will asked to choose a folder.
PLDA then imposes all the PDF files in the folder and in all subfolders. The imposed document is saved to the same folder as the original PDF file.
After the batch is done you are informed about the files that could not be imposed according to the chosen parameters.
You can watch the process of page imposition of a file as usual, in addition number of files to process and the name of the file just being imposed is shown.