REI:“Well, Captain Katsuragi and Doctor Akagi are waiting at the cage.”
After her line she moves out of view, covered by Shinji’s back.
Shinji leans forward, as if to follow Rei as she withdraws.
SHINJI:“Ah...”
SE <<Sound of the door opening off-screen.>>
Kendrix: ...nor to watch the girl that just accepted his decision without any further comments whatsorever walk to her death. His sudden movement here also shows how much that line affected him. This is completely new to Shinji - she isn't doing anything to urge him to fight in EVA, and she isn't angry or at very least displeased.
There's also his protector's instinct kicking in here, when she says she's going to prepare for the battle and he shows that almost instinctive "following movement".
