How Was This Image Created?

Both negatives were shot using 35mm film. The negative on the right was shot in 35mm format with each individual image measuring 36x24mm. The negative on the left contains a single image that is almost 2 1/2 times as big as those on the right and goes all the way to the edge of the film - beyond the sprocket holes. Does anyone know what kind of format this is or how this photo was created?