Diana could be serious, and would be when the time came, but thus far, the dragon hadn’t even caused any visible damage. Surely it had, because dragons were not meant to fly or roost amongst human buildings, but Diana had not actually witnessed any terror, horror, or destruction. So it was not a danger yet, and might never be, for her. Although she was fairly sure she could be burned, unequivocally, so a dragon would be dangerous to her where other things might not be. A little extra excitement, if anything.
Still, John Constantine had cautioned her that people did die here. This was not a realm of eternal life, and though she and Thor were resilient, neither Asgardians nor Amazons nor Gods were eternal. Diana’s excitement was still very much present, but somewhat muted, as she considered that. “I do,” she said with a nod, and a little rueful giggle, both because she knew it was silly and because Thor had known without needing to be told.
“But if this is not New York, then these are not New York’s citizens. They might not even be citizens, which means the dragon isn’t hurting anyone, really.” Diana shrugged, chewing on her lower lip for a moment as she considered what the implications of that might be, whether or not the people potentially in danger further into the city even were people. “But if they are, and if it is hurting them, then I suppose we ought to do something about it.”
Her pace was a bit slower now, a bit more cautious as she took in her surroundings and scouted ahead more than she had been, but she did allow herself one small complaint. “I find it very rude that all the humans killed all the fun mythical creatures before I even left Themyscira, and now there’s one here and I still might have to kill it." Diana paused, considering. "I'm not going to kill it. I will shoo it if absolutely necessary and if the humans want it dead that badly they can learn to slay a dragon. I never have before so we're on even ground."