When you reply to a comment you will be presented with a box that says "POST REPLY" The bottom 1/3 of that box is where you type your comment and below that comment box is a blue link that says " ADD IMAGE TO POST". Click on that link and you will be redirected to postimage.org . On that postimage.org page you will see a button that says "CHOOSE IMAGE", click it and choose where you want to get your picture from (most likely your PHOTO LIBRARY). If you click PHOTO LIBRARY you will be directed to the pictures on your phone. Choose one and click ADD. You will then be sent back to IS. Click POST. Boom, done.