i think i see - the lighting reflection is causing the eye to “think” the edges of the paper are moving. Almost like a little wind is hitting the paper there. Its easier to see the very corner is “flapping” a little when the camera is moving.
I have a feeling its due to the light reflection on the white paper. See if changing the paper color to a darker color, or, the reflections are not as bright (the bloom maybe) resolves this.
Watching the shadow of the paper and playing in slow motion with a paper lined up shows no actual movement, but, the effect is tricking my eye to think the corners are “flapping” and moving. … its a lighting illusion happening from the contrast of the light, the camera movement, and, the shadows.
EDIT:
Just trying to figure it out …
Playing on .5 speed shows no actual movement.
Playing 2x speed is way smoother and shows no movement.
Now that i know there is no movement and my eyes have been “shown” the illusion, i no longer see it on normal speed
The papers seem to not move anymore … hmmm …