The 'curtain' is only seen on one of the Z10s and never in any of other Z10 pictures we have seen, and that makes me doubt if it was some deliberate measure. Since these birds are down and undergoing field maintenance, it could just be something the ground crews were using that was just stuffed into a corner when the picture was taken.
I am also not sure how much the old 'pilot on top, gunner below' arrangement still applies to attack helo pilots.
Many if not most modern militaries that operate attack helos now operate under the 'co-pilot gunner' system, whereby both pilots are equally qualified to fly the helo and operate the weapons systems, with both cockpits offering the full array of functionality to allow either to fly the plane or operate the weapons systems.
This approach is more costly in terms of training of the crew, but offers many significant advantages in the form of increased survivability (the helo won't crash if one pilot was taken out or his controls disabled/damaged), better operational flexibility (the pilots can switch roles at will, if one pilot sees something through the gun camera when operating the weapons, he can take over flying to find/investigate instead of having to verbally direct the other pilot to do so/sometimes, taking control yourself is faster and offers a better chance of evading an attack than shouting a warning etc) and improved logistical flexibility in that any pilot can fulfill any role, so if you loose a gunner through attrition or illness or whatever, any spare pilot can take his place instead of needing a new guy trained specifically as a gunner.