That area below the posts is where people put their "signature". Go to the top of this page, click on "my profile", and scroll down. There will be a place to put your "signature" in a box. You can type something you want to say, or put a picture there. In order to put a picture there, you have to have the URL address of the picture first. Find the URL by right-clicking on a picture. A little box will pop up. Down at the bottom of the box, click on "properties". Another box will pop up, and the URL address will be about in the middle of that box, starting with "http:".
Once you have the URL, you can put the image into your signature box by typing the URL right smack in the middle of .
Example:



That should cause the picture to show up in your signature, below your post.