The space was to keep it from working. You don't want any spaces when you do it to put in a picture. If I hadn't put the space in there it would have tried ton show that as a link or picture.
Here is an example. The first one I won't put any space in and the picture will be there. The second one I will put a space in and leave out the ] bracket and you can see the URL of the picture. it won't show the picture.
[img http://www.hazelnet.org/icon/xxx/boobies1.gif[/img]
Ron