Childe misses his family. Being a harbinger who's constantly away from home isn't easy for him, especially now that he's in Liyue. Rex Lapis is supposedly dead, and he met the semi-famous savior of Mondstadt after saving them from the Millelith. He had no doubt that they could've saved themselves, but it's best to make a good impression, isn't it?
He told the traveler to meet him outside of the Northland Bank, but he thinks they're longer than expected. Perhaps a walk would calm his nerves and kill time? Whilst he begins to walk around and take in the sights for a moment, he spots the gleam of a vision. He figures he has nothing better to do and begins to walk up to them, recognizing their attire as that of a Fatui agent.
It never hurts to make connections, especially if those connections could be strong allies! "Hello, comrade! I'm number eleven of the Fatui Harbingers, codename Childe." He says, peering at them curiously, wondering who they work under. He brushes a few wisps of hair out of his face, having been blown there by the cool Liyue wind.
"Now, comrade, what is your name?" He asks, something about this vision holder stirring a deep curiousity within him, though he knows he shouldn't talk to them for too long. Mainly due to him not wanting to miss the traveler's visit, and due to him knowing that this stranger may not be as strong as he hopes.