Step One:
Once you have entered the text for you comments, click on the attachment icon. It looks like a paper clip.
Click thumbnail to view full size screenshot
Step Two:
A new window will open when you click on the attachment icon. Click on the browse button and navigate to the image that you would like to upload. Use a separate upload button for each image you would like to upload. When you are ready, click the upload button. Once the images are done uploading, simply close the window.
Click thumbnail to view full size screenshot
Your images will be automatically displayed as thumbnails within your post now. They will appear when you post your message, or if you click to preview your post.