Carlos has been living in a desert for a while, so wandering in the desert isn't unusual. And seeing something unusual in Night Vale happens almost every day, so he's not as startled as he would have been had he not had that experience. Still, it's a little jarring to see a suit of armor talking to him and sounding like a young boy. Still, it's Carlos, so he's more curious and excited than startled.

"Neither did I! Mostly endless deserts tend to be pretty empty, in my experience. I'm Carlos. Carlos the Scientist. ...Can I just say, your suit is really fascinating! I've never seen one quite like it."