JMo could have used animalistic, which would mean lust, passion, raw — which I love my saucy NC-17 fanfiction too — but “human” — that takes on a whole other different meaning. It’s a real connection between them.
While “a very human moment” could mean something more than raw passion, you also need to consider what Jennifer said in the sentence before.
“In that adrenaline, she realises that this person has participated and made it possible,” Morrison says of the lip-lock. “It’s a very human moment.”
It’s an adrenaline-induced kiss, meaning it’s a kiss they share in a moment of passion. That is not to say it is *just* lust, but it IS a hormone-induced, heat-of-the-moment kiss. Maybe there is a deeper meaning, as you say, but maybe not. Sometimes a kiss is just a kiss and not a declaration of love. Note, this is my opinion without knowing more about the context. I’m just interpreting based on what Jennifer said.
It’s also interesting to note that two times we’ve seen Emma in the present kiss a guy (present, not a flashback), it’s been her to initiate said kiss. She did it with Graham and it’s happening with Hook.
It’s true that Emma is no shrinking violet. She is her father’s daughter after all. Though Graham was the first to kiss Emma, and later she initiated a kiss with him. Also, Emma was the first to say she loves Neal (twice). In the flashback kisses with Neal, Emma leans in at the same moments as Neal, showing it’s mutual.
"That’s how you know you’ve really got a home. When you leave it, there’s this feeling that you can’t shake. You just miss it." Neal Cassidy