Here's how that works.

1. The layout contains a special footer: {{cp footer}}.
2. cp footer contains a card called "wagn badge"
3. wagn badge is basically hard-coded, and it pulls in the image from wagn.org
4. *css contains the following CSS to make it look nice (and make it so the words overlap the image)

#cp-footer .wagn-badge {
   display: block;
   position: relative;
   left: 8px;
   margin-top: 10px; 
}
#cp-footer .wagn-badge img {
   position: relative;
   right: 16px;
   z-index: -1;
}