I noticed the coolest thing!!
Selina uses the pet names “honey” and “baby” throughout the movie.
When she talks to Penguin and Gil, the DA, she calls them “honey.” She’s emotionally closed off and undercover, so she doesn’t put her heart into flirting, which makes sense. She uses “honey” to gain info from people; she doesn’t mean anything by that name. The second time she bumps into Batman (when she’s burglarizing the mayor’s house), she even says, “listen honey, I didn’t kill nobody!” She doesn’t trust Batman yet; she doesn’t know if he has the same motivations as her.
But when she rides home in the taxi and phones Annika, she calls her friend “baby.” “I’m coming home, baby.” “We can leave the city tonight, baby.” Annika is her close friend, so it makes sense why she uses that sweet pet name. Selina deeply cares about Anni, and you can tell because baby is genuine compared to honey.
Later on, when Selina talks to Batman by the signal and asks who he is under the mask, she calls him “baby,” and they share a kiss. Selina opened herself up to working with him now, and she’s willing to call him a genuine pet name because she genuinely kinda likes him.
When things go south, and she asks Batman to help her kill the shady cop, and he refuses, Selina is hurt. She thought he was on her side, but he wasn’t. She puts her walls up again and closes him off. “Don’t worry, honey. I got 9 of ‘em.”
And finally, during the big fight scene in the Garden, she decides to stay and save Batman’s life. He’s hurt, and she consoles him by saying, “it’s ok, baby. It’s over now.”
Basically, you can see the filmmakers/Zoë Kravitz put SO MUCH care and love into every detail of Selina’s character. Selina is usually so closed off and elusive, but you can tell how much she cares about someone by the pet name she uses for them! It’s a fascinating aspect of her character!
AND it’s helpful for fanfic writers: Selina is only genuine when she calls someone “baby!” “Honey” is only uses when she’s angry or undercover!