Unlike some social media sites, this website requires that an image you wish to post most reside on a web-accessible service (photobucket, postimage, fotoki, Imgur, google image, etc). I had used photobucket, now use postimage.
Once uploaded to the service obtain the URL (address) of the image - the http-thing. Copy the address.
Using the FineScale posting dialog click the image icon and paste the address which you just copied. Add the image. You may add multiple images by advancing the cursor and repeating the process. Complete the post dialog by clicking the submit button.