Harvey had gone down to the dining room to find food. There had been some sort of skirmish going on nearby, but he really didn't care overly much about what the humans were getting up to, so he went in and filled a tray with all kinds of different foods. Admittedly, some were things John had eaten before, but he'd enjoyed the memory of them and he wanted to see if the actual experience would compare. He filled a plate with things he thought River might like (fruit, a few pastries, things like that) and then went up to the girl's room.
He had only just stopped in front of River's door when he heard her voice, so he carefully opened the door and stepped in. "Hello, River," he said with a smile, not fazed in the slightest by how she was sitting. He lived in John's head, after all. "I brought you some things to eat, although I must admit, I'm unsure if they're to your liking."
Walking over to the coffee table, he set the tray down, and then stood back, his hands clasped behind his back. Having a physical form was entirely new to him and he really wasn't sure of everything he was doing, but he could fall back on his memories of John's memories if he needed to.