Showcase Slideshow Image Positions

I installed showcase and I am trying to figure out how to add pictures to the slideshow!

you can have a look at this: http://joe.bastarde.at/

the picture location is http://joe.bastarde.at/theme/image1.jpg

hence my image location in the showcase menu is http://joe.bastarde.at/theme/

and the image is image1.jpg

I added a title and a description!

any help?