The cameo will cut any lines you designate as cutting lines. You can use already printed icing sheets, such as Lucks:
You may cut these in any desired shape, circles, squares, whatever.
However, if you want a specific design, then you would need to print it on icing sheets with an edible image printer. The cameo uses registration marks that are also printed on your icing sheet. It reads those marks and cuts out the image exactly.
Right now, I have to get ready for an appointment, later, I will make up a sheet and post a couple of pics to show you how this works..