Ice cream metaphor for the entire plot
Spoilers:
When watching the ice cream scene I couldn't help but think that it must have been a metaphor for everything that was going on in the movie.
At first when Tracy's character tastes it (sees the would-be husband) he is suprised as it was not what he expected.
He then gives it another taste (akin to his conversation and thought process about the marriage thing), and then finally decides that even though it was not what he intended he finds it to be alright anyway, similar to how he decides that he is fine with them getting married in the end.