This is a hardware difference, not a problem. I'm not sure at all if this would cause any issue. Just raising an attention here since I was asked by one of the users.
Type-B robot looks straight ahead
Type-C (incl. NXOpen) looks slightly down:
Assuming at both poses above pitch is 0 degree at head joint, there maybe possible problems for the users who own both Type B and C (eg. application that uses head angle of initial pose looks).
closing. if we still need some action for this, please reopen this ticket