Use the supplied illustrated first frame with a locked side camera. Keep the conveyor frame, legs and both roller axles stationary. Advance the upper belt toward frame right. The same single parcel travels a short distance to the right with the supporting top belt while its triangle and upright orientation remain unchanged. Keep the parcel bottom in visible contact with the belt; do not let it hover, roll, slide backward relative to nearby belt marks or split into multiple boxes. The roller surfaces may turn around their fixed axles. Stop while the parcel is still fully supported before the right edge, then hold. No camera tracking, no falling off the belt and no seamless-loop claim.
