The Chinook is far more obvious than the journo, who could as easily be a serviceman in civvies. Chinooks don't deliver journos to their back doors, any more than servicemen disembark in civvies, so it's clearly not a realistic portrayal of anything.
To my good lady wife, the ad said: "Only a handful of servicemen will be home for Christmas", with the subtext "Waitrose knows that even as the rest of us celebrate with our turkeys, Chinooks (and the rest) will still be doing their duty".
I must admit that that was how I took it, too.