Peter's vision of the impending future marks the first time that all the main cast of characters all come together in one scene.
This is the first episode in which the Haitian speaks.
In this episode Isaac learns that he doesn't have to be high to be able to see visions of the future.
When Hiro sees the prophetic painting of him fighting a dinosaur he says he might step on a bug and change everything. In the 1952 Ray Bradbury short story "A Sound of Thunder" a time tourist goes to the Jurassic, steps on a butterfly, and changes the subsequent course of human history.