After visualizing a photo becoming a video in the fusing process, I wondered if the photo would become a video if it were animated with the 2D editor.  So I experimented with some side by side photos on the timeline.  Turns out that if you animate two in a row they will accept the Classic Gradient Wipe.  In other words, and animated still photo equals a video clip.  Cool, huh?

 Thank you Sylvain for jogging my brain.