Automatically include image with "Press This" bookmarklet?

I want to automatically include an image while using the “Press This” bookmarklet. I see in the documentation that I can include an image location in the the URL’s query string, as in:

http://example.com/wp-admin/press-this.php?u=&t=&s=&i=IMAGE_URL

where IMAGE_URL is something like http://example.com/picture.jpg.

How can I get press-this.php to accept this URL and automatically include picture.jpg in the post?