In Evangelion, whenever camera pans at some object, it always means something symbolic. Like when later Misato talks about her father at the bar with Ritsuko, we get close shot at Misato's cross, representing its importance as an object that connects her to her father. Now why a close shot of spilled drink? I don't know if it was a cold drink or milkshake but I couldn't find any event related to a spilled drink or something similar in TV series related to Misato.
Why would Anno chose to show a close-up shot of something simple as spilled drink twice? It's got to mean something to Misato, any ideas or theory?