I've been open for 6 to 8 weeks, and had 2 sales. You have to be patient.
One thing I will say is that your pcitures aren't clear. Looking at them, it seems more like you're selling PDF files or something for scrapbooking. What I would suggest, is using 2 images. Your front image that people would see should be displaying the frosting itself. People then know exactly what they're looking it, with it already on a cake. Then, once the item has been clicked on and opened, a second image on the image selection panel should show the samples that you currently have as your main image.
Now, people who come across your listings individually won't be inclined to pay much attention to it. The featured items at the top of your shop, however, make it clear what you're selling, and if people happen across your shop as opposed to your listings, it'll be a bit clearer.
In less rambly terms: use images of your frosting as opposed to the available designs to pull people in. That, and, of course, be patient, and try advertising outside of Etsy, either on free blogs, or on payed websites. There are -plenty- of blogs out there who specialise in cake making, decorating, and eating ;P contact some. It's a simple matter of searching for some!
