Hmm yes I've often wondered about such helmets, can't imagine they were lightweight 'dress' helmets but then I imagine rarely were they in the front line to need the real thing! Looking at the first pic the helmet liners are obvious, could the shiny version be one of those?
During the First World War, when steel helmets were first issued to British troops, a short-lived fad was to drill holes in the helmet to mount regimental cap badges. That, of course,weakened the helmet's ability to withstand bullets or shrapnel in that area, and the Powers That Be quickly made it a military crime to do so.That in fact is a Lacquer painted steel helmet. You can see the steel helmet chinstrap attached at the back of the helmet the way that many GI's preferred to wear them. A couple of high profile generals wore parade dress liners under their steel pots and when not in a combat zone or situated in a rear command area, would simply wear their parade dress liner when meeting other high ranking officers. Most of us have seen picture of Patton wearing a parade dress liner in the rear areas but when in a combat area he wore his steel pot over the liner.
But you're right about making yourself a target for an ambitious sniper. I guess ego outweighed common sense in certain individuals.