When Koenig talks to the older Helena, the regular one can be seen standing directly in front of the door. However, the close ups on her show no door but a large expanse of scenery extending some way into the distance.
In the frontal shots of the children, the girl is clearly shorter than the boy, but in the shots facing Koenig (from behind the children), they appear to be the same height.
Koenig: Victor, a space phenomena we don't understand shifts us billions of years across space. As incredible as that is, I accept it. But to put us precisely in the exact orbit we occupied around Earth... I know less and less about this universe, Victor, but that's got to be more than chance.
Bergman: Yes, there's a logic to it somewhere, John. There is some frame of order. We may make all sorts of blunders, wander off the path now and then, but ultimately... we belong where we belong. On Earth.
Alan: I wonder if the others made it. If they survived.
Koenig: Did they ever really exist?
The "This Episode" section contains a shot of large domes that wasn't used in the episode.