On a purely technical level, "visual and command" references both German radios and optics. Although German tank design was relatively conservative, especially at the start of the war, their tanks incorporated good optical equipment and effective radios. The latter was especially effective at coordinating German panzers as an effective unit. German optical sights were often quite advanced as well. This gave the early war German tank commanders a better sense of situational awareness than his French, British, or Russian counterparts.

But the Germans' early superiority in situational awareness was not just of a technical nature. Most German commanders did not fight "buttoned-up," which is tanker parlance for fighting inside the vehicle. At the top of a German turret was an circular armored cupola with vision ports all around it. This allowed a commander to scan terrain with the "Mark One Eyeball" from a relatively safe position as seen in this photo of a Panzer IV. Early war Allied tanks did not have this ergonomic design. For example, the earlyT-34's top hatch was notoriously clumsy and did not give the commander a good view and exposed him to fire from the rear and flanks. When the Germans captured Allied tanks, one of the first things they would do if able was replace the top hatch with a German one, as in these Beutepanzers.

So in sum, not only did early war panzers possess better optics and radios, they were a more ergonomic design than their contemporaries.

Sources

Forczyk, Robert. Tank Warfare on the Eastern Front. Barnsley: Pen & Sword Military, 2014.

Zaloga, Steve. Panzer IV Vs Char B1 Bis: France 1940. Oxford: Osprey Pub, 2011.