See only what changes between frames. A frame is compared with the one a few frames before it; what did not move cancels out, and what did is all that is left. It is the technique behind the motion-extraction videos that show a breathing chest, a wobbling table or a plant turning toward the sun, and it works on any clip from a steady camera.
Three views
Reveal blends the current frame with an inverted copy of the earlier one at 50%. Still areas land on mid grey; a moving edge appears as a light edge and a dark edge offset by the distance it travelled. It is the view that makes slow motion readable.
Difference shows the absolute change on black, which is the cleanest input for spotting whether anything moved at all. Highlight keeps the picture where it moved and darkens it where it did not, so the moving thing stays recognisable.
Frames apart
The offset sets which earlier frame is compared. At 1 the view shows fast motion only, since slow drift barely changes between neighbouring frames. At 6 a slow drift accumulates into a visible shift, and fast motion turns into trails. Gain multiplies the difference before it is shown; raise it for subtle motion and lower it when the picture clips.
Steady shots
Everything in a hand-held clip moves, so the view fills with camera shake. Run the video stabilizer first, or use a tripod shot. Changes in exposure and auto white balance also read as motion across the whole frame; lock them on the camera when recording for this.
Preview and export
The preview compares frames the player has already shown, so it has nothing to compare against for a moment after a seek. The export decodes the clip in order and has every earlier frame, so the first frame of the file is the only one with no reference.