Adverts are made by first making the unrealistic assumption that the viewer is in any way interested whatsoever. Then trying to sell some moronic senseless idea and associating it with the unconnected product.
Hilarious, really. The mirrors, for example, reflect both cylinders equally, just not
toward the camera lens... that's not a weight-of-mirror effect at all, because the 'modulation' source claimed is a figment of the camera position.
As for the empty/full picture 'balance', it is essential for such a balance that the arms support AT THE SAME POINT the two sides (like, with a hook and pan)
both during calibration and weighing; those pictures aren't
point-suspended, so a millimeter of offset distance would account for
any apparent effect.
A bit of string hidden behind the upright can wrap around the axle and... instant paranormal phenomena!