During Superman's speech, the positions of the group listening change, to the point where many disappear and reappear, and not always in the same location.
When General Kwan rebuffs the Justice League, the sky in the background reveals daylight, but when John is at the Javelin contacting the Watchtower a moment later, it has changed to night.
Why do Supergirl and the other two have to do it alone? Why haven't they contacted J'onn and kept him appraised like Green Lantern was?
Why must Green Lantern lie in the Javelin and get to back up? The teleporters can send in re-reinforcements.