Katu. Last I heard the site storage was full so I find the easiest way to post a pic is to use the file sharing site. Two buttons in the tool bar. If you put your mouse over the icons one says " host an image" and the other says "insert image".
Before using this button you need to re-size any of your images to 800 x 800 or there bouts. Most camera images are massive and can't be hosted with out re-sizing.
Click "host image", choose your file and then hit upload. The window will change to a couple of text lines. Copy the bottom one.
Then click the "insert image" button and then paste the text into the "URL" box. Hit insert and the image will appear as a code line in the message box. Where ever you put this code line in the post will determine where the image appears. Hit the "preview" button to see the image before you post.
Hope this helps.