you could use the 3rd party web cam setup, and select the source as the normal webcam image
and then set the output image size as much smaller (use the alternative method at the bottom of that setup)
and then set to upload that with the general ftp or similar
if using the customised file creation and upload setup, you can set there to also create and upload thumbnail images of each of the WD web images (Anthony is not correct in saying that WD can not create thumbnail images)