The motion of the speaker feeds signal back to the needle/input device. It matters even more in Jazz/syncopated music. The needle tracks with a force of only 1.5 grams or so, and any motion is greatly amplified. Also if you listen to jazz with the volume low you are doing it wrong. Do you link the volume was low in the club when Sun Ra was recording?

But besides that, those speakers are placed terribly for stereo imaging. Even tucked in the cubby, why place them with the drivers together rather than apart? And those speakers appear to be dreadful anyway. A single 12" driver in a vented / untuned baffle with no midrange or tweeter elements?

So this is definitely set up for aesthetic, not sound quality.