The Movie
The fact that the narrator is in the present but watching a silent movie about the past is deeply symbolic as a representation of passive resignation to destiny. The past and the future become intertwined; the future is written in stone and unchangeable while the present is manifestation of what has already occurred in the past and cannot be undone.
The Photography Session
No matter how the narrator’s mother and father are posed by the photographer the sense that “somehow there is something wrong” persists. This is a very nicely illustrated symbol of a couple who should never have been together in the first place, much less gotten married.
The Merry-Go-Round
That both parents have mounted horses on the merry-go-round is obviously a symbol of the repetitive nature of their marriage and possibly indicative of a pattern of arguing. It is the description of the horse each is riding that is more interesting symbolically. That the narrator dreams his father is on a black horse while his mother rides a white likely represents his own person view of who is to blame for the failure of the marriage.
The Sun and the Ocean
In the movie, on the boardwalk, it seems to be a beautiful, perfect day for his mother and father. The ocean is merry and the sun is making it sparkle. All they can see is the beauty; they are blind to the scene as it appears to the narrator. He sees the sun’s rays as dangerous lightning strikes and the waves in the ocean growing rougher. He sees the future perfectly while they are lost in the fantasy of the present.
The End is the Beginning
The narrator ends by telling us the conditions outside the theater: cold, bleak and wintry. It is the additional information that this day happens to be his 21st birthday—the traditional legal passage into full maturity—makes the conditions of the day symbolic. The suggestion is not just that the narrator realizes the future is never easy, but that the consequences of his dream indicate he is going to have an especially tough time dealing with the process.