on 08-03-2012 11:33 PM
It means it puts your ID on your picture in your listing. It's kind of light and see thru - but it helps keep other's from using your picture without permission. Click on the link below to see one of my completed listings with the watermark on my picture. It's on the bottom left corner.
on 08-03-2012 11:38 PM
When you chose that option your User ID will appear on all of the photos you upload to your listings.
I use it on all of my listings to prevent picture theft-it's free and I highly recommend it.
on 08-04-2012 03:08 AM
see the response to this thread:
"...eBay does not watermark the supersize and zoom images. They only watermark the mid-sized photos, like the one at the top left of the listing."