^ 1) Its a real cover, and 2) Their firm, determined, demeanor may be as a result of all the deaths they are experiencing witnessing, Hinata's cousin included.
I personally consider Naruhina like this. Everyone knows that Sakura is like Kushina. Been said everywhere. What most people neglect is that Hinata is like Minato. They both stalked their loves in childhood. Both step back and let the more dominate one speak. They don't interfere in each other's battles unless they need help. Namely when the usual confidence in the more energetic partner is deflated and they need that boost.
As for how Hinata is dealing with this situation with Sakura. It feels more like Hinata is just waiting. She has said her peace and she may already suspect/know that the Narusaku relationship will never come to fruition. So she is choosing to not take any more steps to say hey dumbass. I'm here and i love you and won't hit you for being a baka. So she will let the Narusaku train ride till it derails and them subtley remind Naruto that she is still here and waiting and then they live happily ever after while Sakura enjoys her mostly loveless marriage as Sasuke decides he needs to reconnect his bonds. Gives Sakura a chance they have a kid and he stays emotionally distant.
^ HAHAHA. Mental Imagine of white-redneck-ghetto-trash Sasuke and Sakura. "Bitch, you burnt the ramen again?" *slap takes of belt and proceeds to abuse the living snot out of sakura for being a "shitty" wife*.
......that escalated quickly.
The hatred is strong in you, young Krazawan.