Tuning in for "Beyond the Wall" provided one particularly terrifying moment in an episode jampacked with fire and blood: The two Stark sisters quite literally facing off. But all this changed when Arya gave Sansa a dagger. This one detail from Game Of Thrones Season 7 Episode 6 could suggest that things aren't quite as fraught as they seem and maybe Littlefinger's meddling has been thwarted. Because while it may have seemed like a passive-aggressive move, it could be a sign that Arya still trusts her sister.
This isn't, on a first watch, immediately obvious. Tensions are already running high by the time the former girl who has no name finds the Lady of Winterfell rummaging in her luggage for the letter. And it also seems key that instead of trying to reassure her about her creepy sack of faces, Arya takes a distinctly threatening tone and even explicitly spells it out: She's considering adding one more face to her collection. But on reflection, this isn't surprising. Sansa is the one who sets the strange, brutal tone of the conversation when her first, spontaneous response to her younger sister surprising her is to say, "I have hundreds of men here at Winterfell, all loyal to me." The fact that this is her go-to response suggests she's expecting violence from her sister.
When Arya spelled out everything she could do to her sister and why she might be motivated to murder her ("I wonder what it would feel like to wear those pretty dresses, to be the Lady of Winterfell, all I’d need to find out is your face.") she makes a pretty convincing case for why it would be in her self-interest to off her sibling. But then she does a quite literal 180, flipping the dagger so the handle, not blade, is extended out to Sansa, and so Arya's belly is exposed to the blade — and this feels symbolic. She then proceeded to turn so her back was exposed to Sansa and walked, not hurried, out of the room. She gave Sansa not one, but two chances to hurt her.
It felt like one long stunt to prove that actually, Arya does, for the most part, trust her sister. That, sure, there may be tensions brewing and unresolved issues, but she knows her sister well enough that she does not feel threatened by her — and while, as she's illustrated with her creepiest ever overnight bag, Arya is a cold-blooded killer who would have no problem taking out another victim, she has not reached that point with Sansa.
This makes a certain sort of sense in terms of the broader plot. After all, it was Bran who gave Arya the dagger in the first place. Given his clairvoyance, it seems relatively unlikely that he would have given his sister the Valyrian steel blade if he foresaw that his doing so would result in either of his siblings murdering the other with it. As such, it seems more likely that it was intended as a tentative truce and display of trust than as a declaration of war.
Clearly things aren't hunky dory between the pair. But this is crystal clear: Arya is reassuring her sister that she's not intending to kill her, at least for now.