The jpg has to be online somewhere, let's say it is at http://wwww.example.com/NotReal.jpg, then all you have to do is type the following, eclosed in"< >" brackets instead of the "[ ]" ones:
[img src="http://wwww.example.com/NotReal.jpg"]
That's all there is to it. I didnt do it directly in my post because the pix were kinda big and I didnt want to bog down the bandwidth for people unless they were motivated to click the link.