When you drag your Slot Machine Stack out, you will see the above stack appear on your page.
You can drop what ever contents you want into the Slot Machine into the stacks drop zones. This can be anything, text, images, etc.
The only setting you can change in this stack is if you want to preview a specific slot number. To do this check Preview Slot? checkbox and choose the slot you want to preview. This is probably only needed if you have a lot of slots and want to see a particular one.
Now preview and enjoy! For an summary of the remaining settings please refer to the Slot Machine Settings section.