These are the omnitrix after they have been put on the cupcakes. It's hard to tell from the picture but these are the extra large cupcakes and the fondant piece covered the entire thing so they were each quite large.
I decided they were too cute to just sit on a platter, so I covered the smallest of my cupcake boxes with black paper and used that as a center piece to elevate a couple of the cupcakes. Unfortunately, I didn't get a picture of the entire thing all put together. I also made a Happy Birthday sign that attached to two wooden dowels and stuck inside of the cupcakes sitting on top of the box. The sign is below.
For this I used a yellow piece of cardstock and then decoupaged it. It made it shiny and a little more stiff. We had cut the letters out of fondant so I outlined the letters with black piping gel to help them stand out against the yellow paper. The sign stood up on top of the cupcakes on the box.