Just wondering - if we delete a picture and replace it with another one (let's say after doing some editing) what will happen to the comments on the one deleted? Is there a way to just replace a picture or do we have to upload the new one, delete the old one and pretty much start from scratch with the commenting? Thanks :o)

You can't replace images in the way your describing. You can upload an edited image, but it's no different from uploading a completely new image. If you delete any image the comments are lost (unless you cut and paste them manually into a word document or something like that).

That's what I thought - thanks for the response! :o)

From the FAQs:

How do I update an image that I've uploaded?
You can update the title and description of an image, but you cannot re-upload an image to take the place of an older image. This is because it could be confusing as to which version of the image people are referring to in the comments and because the old votes wouldn't necessarily be the same for the new image. If you want to change an image or update it, please just upload it as a new image and (optionally) delete the old one.

Thank you.