Shit
Ellen is seen walking down the hallway to answer the door and she repeats her mother saying, "shit, shit, shit." It is a symbol of how the parents choices are learned by the child at such a young age.
Cream Cheese
Dan gets cream cheese on his nose and Alex points it out to him, and they lock eyes. It is a moment of flirtation that is a symbol that they are both allowing their flirtation to boil over rather than be tamed by their wills.
Spaghetti
Dan has leftover spaghetti sauce in the refrigerator at home while Alex makes fresh spaghetti, her "specialty" for him at her place. This is a symbol of how a man can easily assume that the newness of something is actually better than the longevity he already has.
Sharp
Alex comes into Dan's office to apologize for cutting herself. She sits in front of a cup full of sharpened pencils which symbolize the chance that she could hurt herself or him at any moment.
Too Close for Comfort
Dan is seen listening to a tape Alex made after he called off their relationship. He jumps as Beth touches him. This is a symbol that Dan is so involved in the mess that he's created that he is living in constant fear of what may happen to him if he tells the truth.