The stop signal plug is dark but it can be seen shining as it reflects the light.
RITSUKO (OFF):“...we surmise that the pilot’s mental instability was the main cause.”
EvangelionFan: Surprise! It's a cross! ... okay, I should be used to the religious imagery by now, but this is probably one of the most interesting uses of religious imagery in the entire series: a cross has been jammed into the entry plug port of the Evangelion, as if it were a stake into the point where pilots synchronise with the core.
Sailor Star Dust: Pointless Religious Symbolism, ahoy!
thewayneiac: That is actually known as the Signal Termination Plug, and its purpose is to make sure no nerve impulses get from the Eva's brain to its nervous system.
