She lowers the scope in alarm.
Misato:“Hold the phone… They're gonna use an N² Mine!?”
Reichu: Talk about ending up in compromising positions.
MDWigs: Is Shinji looking at Misato's bust here?
Reichu: Well, why look outside when all the scenery a young male could ask for is right in front of him?
OMF: Though it's a little ambiguous (and what isn't in this series?), I think he's staring at Misato's cross.
Sephizim: Given what we know about Shinji, it is as equally likely that he's staring at her chest as it is that he's absorbed in such a mundane detail as her cross. Could even be both, or that one stemmed from the other.