Hi Newscaster,
Possibly - it means that through the routes served by Cargolux, the Etihad name and look will reach parts of the world that it so far hasn't! I personally expect that a limited number of the Cargolux planes WILL bear the EY logo or livery.
Clever marketing. (Just in the way that the Qatar Airways logo and livery and name is seen in places as far afield and diverse as Palma, Toronto, Denver, Houston, Brasilia, Havana, Edinburgh, Nice, Venice, Washington, Corfu...............but QR doesn't operate to any of those places, but the Amiri Flight regularly visits there weraing the full Qatar Airways logo).
There is method in the madness of EY, I would say........
AB6