> I can only suggest something like
> 
> (equal (org-element-begin link)
> (save-excursion
>   (goto-char (org-element-contents-begin paragraph))
>   (skip-chars-forward "\t ")
>   (point)))
> 
> (equal (org-element-end link)
> (save-excursion
>   (goto-char (org-element-contents-end paragraph))
>   (skip-chars-backward "\t ")
>   (point)))

This should be fine, it's what we do in many places in org-latex-preview.

> > - Does org-element provide a property that can help here? I tried
> > :pre-blank but it was nil, I'm not sure what it does.
> 
> :pre-blank is for blank lines before contents. Leading whitespace is
> considered a part of the paragraph:
> (paragraph (...) "  " (link ...) "\n")

Good to know.

I've attached the latest version of the patch.

- 'justify is no longer an option

- 'left is now supported as a value of `org-image-align', although of
  course this is a noop.

- Leading and trailing whitespace are handled correctly.  The image
  overlay swallows up any trailing whitespace if there is nothing else
  on that line.

- Right alignment will still fail in some odd circumstances, such as if
  there's an overlay with a display property to the right of the image.
  To see an example of this, turn on whitespace-mode and try to
  right-align a standalone image.  I don't think it's worth handling
  cases like these at least for now.

Karthik