The girl that Superboy is holding is Phantom Girl. She's a member of the Legion of Superheroes (who are from the future). One of her powers is the ability to travel from Earth directly to the Phantom Zone without needing a Phantom Zone Projector.so the Phantom Zone here works differently than I’ve previously seen it in other DC projects. I was always looking at it like you had to use a device to send someone there. I still don’t understand how Superboy ended up there.
She saved Superboy by phasing into the Phantom Zone. However, that took a lot out of her and she's knocked out.