If you look at the propensity of photos on this site, kill rings in large numbers, or at all are actually somewhat rare. I don't think that's because all the tanks and crew are new to battle.
I have read that with USA aircraft in WWII the pilots almost never flew with kill markings on their planes. It was for propaganda photos only.
As LAH 1 SS pointed out, advertising your prowess just makes you a target. Plus pilots, like tank commanders and crews moved around from tank to tank as units got damaged, destroyed, repaired and replaced by new tank/plane types.
Since propaganda photos are most prominent to the public, we associate that with, "normal". Cyberia's Ost Front photo collection is more representative of the real war then the regular press then or now.
