Ruby was not a happy demon, though that was likely an oxymoron. Happy demon? No, she was pissed off. This was pretty much a constant state of being for her. She was still convinced that Lilith had sent her to this hell hole. No, it wasn't a hell hole. Ruby had to rethink that, since she'd been to hell and all, but it was pretty bad here. Maybe it was some kind of limbo, or something. She was almost certain that Lilith had sent her here, but why? And why send Sam too? And a Dean that was from a time before them?
Just what was Lilith up to? These were the questions that were plaguing the unhappy demon woman, as she walked. She wanted answers, and she wanted to kill Lilith. She'd have to stand in line of course, she knew that Sam more than wanted a piece of Lilith too because of what happened to Dean back home. It could still happen to him here, Ruby had no delusions about that, but she was going to try and help them prevent it.
Ruby actually cared about Sam and what he thought of her. She did feel guilty for lying to him before about being able to save Dean, but now she was really going to do it. And if they couldn't save him, she would find a way to get them into hell and bring him back.
Right now she was walking down the street, playing with her knife, daring anyone demonic to mess with her.