Sequential art! It forces you to fill in the missing action. The brain is a pretty amazing thing.
Telling a simple (very simple) story with Photoshop is pretty easy. I just opened the two photographs, checked the image size, started a new image twice the height of one of the originals, then copy and pasted both photos into the blank image, one atop the other. The borders were added with the "stroke" function in blending options. Thanks to Jeff and Allan, who taught me pretty much everything I know about Photoshop. (They know far more.)