The image was an in-camera double exposure achieved using the Canon 5D MKiii. I took my base image of my wife and I in our studio at home. Camera was set to the 10 second timer on a tripod at f/11 - ISO 100 and 1/100 sec. I used two Alien Bee b800s on their lowest power pointed at a white backdrop to back-light and silhouette us, which works better for the double exposure.
The b800s were angled toward the backdrop with no modifiers, such as grids, softboxes, etc.
The second exposure was a frame of downtown Joplin, MO, our hometown. It was shot at f/3.5 ISO 100 and 1/8000 sec. I intentionally underexposed this image significantly, so I could boost the exposure and whites in post (including two additional graduated filters with boosted exposure on the sides), which would eliminate the bleed of the second exposure over the first one . This resulted in a nice white background/canvas and two crisp subjects that have a nicely exposed second exposure within them.