Well the BB Image code puts it in so you can click the thumbnail and get the larger image in your gallery.

If you look at the Direct Link code, it gives you this:

http://www.ball-pythons.net/gallery/files/1/0/4/0/9/pastel_0321094.jpg

if you wrap that in IMG tags, like this:
[img]https://ball-pythons.net/gallery/files/1/0/4/0/9/pastel_0321094.jpg[/img]

It will work like you're asking...