Final Scene Interpretation
If Jack is supposed to represent Lars Von Trier, then the final scene (Jack climbing around the broken bridge) depicts him sticking to his vision of filmmaking (risque and divisive), despite being given ample opportunity to make amends and take the safest route (walk with Verge to his known destination).
The missing middle of the bridge represents the beaten path--so worn out--that it has finally crumbled (a representation of the movie industry and its direction towards what's safe and profitable). The path he decides to take by climbing the walls is one that is not developed and dangerous (films such as these, which are not entirely mainstream and often misunderstood).