maybe post the specific video so we can relate better to your comments.
i owned a Dobbin's Plinth'd and refurbed Garrard 301 that as i recall was dead solid steady appearing to the naked eye. but with a 50+ year old turntable anything is possible.
garrard 301 and its' restorations
i was looking at a recent you tube video of a restored garrard 301 in action. the platter motions while playing an lp were very "wobbly" and bouncy ,like it was tracking a warped record or a spring in the suspension was "detuned" is this an optical illusion or is this normal to the idlers ?. i've never seen this on a vpi ,acoustic signature ,technics 1200 direct drive , kronos ultra high end etc .