Indeed and its very simple.
1.) Copy your image from whatever program you have it on, Photoshop, SAI, Paint, etc.
2.) Use Firefox Browser (other browsers don't work) and get read to upload an episode like you normally would.
3.) Use your Browser's Paste option (usually at the top of the page under EDIT) an tada! Instant Illustration. Control V doesn't work though.
Mind you, while you need to use Firefox to actually get your illustration posted, it will still show up in other browsers.
Easy Steps to Adding Illustrations to your Novel