despite being a mechanical device a visual shake is an issue, perhaps if you place on your hand on it or on the cage you could feel something, but not visually nor shake your entire case, and if its not correctly held in place, well, god knows but that cant be right, specially because hdd doesnt have much tolerance to impacts or shocks and vibrations also doesnt help the cause, it could cause bad write or read on some more extreme cases, none the less, unless your case is made of paper and then hdd isnt perfectly in place and screwed in, i wouldnt trust it any longer.