Is a length contraction just a visual thing?

Won't quibble much over that highlighted, but will point out no material object can move at c relative to any other material object (excluding dubious inferences re cosmic redshift). Only asymptotically approach c, and practically, that will almost exclusively apply only to charged particles typically either cosmic rays or those generated in terrestrial particle accelerators.

No argument with the intent of what you say now. The problem was in earlier stating SR is ONLY concerned with such things i.e observation or merely theoretical calculation of kinematic effects.
There is far more to SR and it's application to many disciplines, from GPS to particle smashers to certain aspects of atomic spectra to practically all of EM. Which are all about interactions effected by relativistic motions. Designating observer vs observed is either completely irrelevant or arbitrary in such situations.

My point in my post # 342 and #559 is true .
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My point in my post #542 , is that to the object realitivity means nothing .

An example ;

Moon to the observer , an object with an observer goes past the moon at light speed . While this observer sees the moon contract because of the speed of light ,
the Moon does not change its properties because the observer is going at the speed of light .

That is my point .
Nope: it depends on where you're taking the measurements from.
I don't think you guys are getting Riv.
He's simply asserting that the relativistic observer must measure the properties of the Moon remotely.
Whizzing by the Moon at .9999c does not cause the Moon itself to undergo any time dilation or length contraction. Those effects are a property of the relative motion between the two FoRs.
Anyone else who wishes to stop off at the Moon (in its rest frame), while the relativistic observer is whizzing by, does not observe or experience any dilation or contraction on the Moon.

That's really all he's saying.