[Kevin Blum] “The effect is at 40 seconds and again at 59 seconds.”
The same matte is used for both, but you will notice that in the first instance, the content fill is different for each panel of the final composite, while the matte/panels become filled with a single source image in the second and flashes over in segue to the next scene.
It probably could be done in FCP in a couple of steps, and a lot of layers, if you insisted on staying in the editor, but sometimes, as Dave suggests, its better to get into a compositor.
I see the effect as a classic A/B/travelling matte, but in this case, the matte reveals either a single background plate, or a background source that is itself a composite, using the same values for motion and geometry as the travelling matte itself. Matching those values would be the tricky part.
National Geographic specifies a treatment something like this for some of its’ series, and they did send out a Media Composer template — but I was a Final Cut user at that point, so I re-did the effect in SHAKE — kind of a Rubik’s cube of crop/motion/size adjustments. The show was “Hitler’s Stealth Fighter” if you are slightly interested and can find the broadcast version. The show title is dropped in most streaming versions.
Good luck.
jPo
“I always pass on free advice — its never of any use to me” Oscar Wilde.