Xylotile

Most of you are familiar with the movie Interstellar ft. Matthew McConaughey. The scene I would like to discuss is when Romilly (David Gyasi) waited in the ship while the other members flew down to the planet to observe it. When the crew came back to the ship they were gone for what seemed a couple of hours, but for Romilly they were gone for 23 years. This is a big if, but what would Romilly see if he could spot the crew members from below. Would they be moving slower since time is different in the ship and on the planet? I'm not sure I posted this in the correct section, but I couldn't find anywhere else to put it.