I’ve watched this scene (and the episode, duh) several times now, and that vein on the side of his head looking like it’s about to burst any second is killing me. Because Emma remembers, and he’s relieved and she called him “Hook” again and maybe he wished she would reach for him, touch him just for a split second. That vein is screaming “I need to show my emotions and maybe even cry out of relief and how much I love you but I need to restrain myself because that’s not what you need right now”. You can BET YOUR ASS on that it almost kills him to not be allowed to touch her in that moment. Because he knows her, and he can read her so he understands she doesn’t want that in that moment.
And I think we all understood his question, “Did you miss me?” actually meant “God I missed you, Swan."
Because, lbr, Emma just had a bunch of memories enter her head all at once and the man that proclaimed his love for her a year earlier is standing there in New York City with her, having crossed realms to reach her because when she was separated from her family she was told she would never see them again. But there he is! The man that clearly loves her and has never let her down. Sure, he’s far from an angel but he’s there for her. Emma is, in this moment, still officially together with Walsh, whom she now realizes she needs to end things with. She’s unsure if she actually loves him, and remembers he proposed to her the night before. And Hook is standing there with her, and she remembers that maybe she actually liked him, or probably more. But that’s not anything she’d ever actually say anything about in this situation, mainly because she’s in shock. What is reality? What has happened to her family? Why is Hook the one to find her? What is she supposed to do with her fake life in New York? How will Henry deal with all of this? Should she tell him? How long before they need to go back to Storybrooke? Is someone dead? WHAT THE FUCK IS GOING ON, is basically what I imagine must be going through her mind right then.
So back on topic. Hook wants to touch her so much it pains him, but he doesn’t because he knows her. Emma would probably like to run but realizes she’s the savior and on some days that can really suck, like this day.
Then they finally arrive back in Storybrooke, where Killian attaches his precious hook again and we get this scene.
Finally, he gets to touch her. It’s small, almost like he doesn’t dare to. It’s interesting, however, that he doesn’t touch her with his real hand where he’d actually be able to feel her. The hair-touching is quite similar to the scene in Tallahassee (I don’t have a GIF but I’m pretty sure every single CSer out there knows the scene I’m talking about), except in Tallahassee he uses his real hand, not his hook. In Tallahassee he’s cocky, confident and not quite sure who this woman is but he’s intrigued. In New York City Serenade he’s more vulnurable, for several reasons, number one being the elephant in the room they’re not speaking of (i.e his attempt at a TLK). And the wonderful scene is followed by her trusting him to watch after her son, (one of) her true love(s). The moment she asks him, he stops grinning and turns serious and is an actual puppy dog when he watches her leave.
Maybe he just wanted to touch her again.