WARNING: This article includes SPOILERS from Superman.
"In an interview with Entertainment Weekly, Gunn shared more about Alcock's Supergirl cameo and how it was used as a way to give the DCU audience an introduction to the Girl of Steel. Gunn stressed that it was important to have Supergirl at the end, as he shared the following:
James Gunn: But for me, the main reason for Kara showing up is to show that Superman not only risked his life to go save a dog that was his dog, that so many of us would do, he was watching the dog for somebody else. The dog's a pain in his ass. He didn't want to take that dog. She's off being irresponsible. He doesn't want to have to watch a dog. He's having to save the world every two seconds. And even still, he goes to the ends of the earth for that dog.
To me, that's one of the most touching things in the movie. Earlier, when Lois says, "It's just a dog," and he says, "Yeah, not even a very good one, but it's probably scared," it just shows you the depths of his empathy. I find that so touching. Then, when you find out at the end, it's not even his dog; she just left it with him."
