There are several unique Elysium version scenes. The first one begins on Day 9 within the story; it's setup in a way where the MC tells stories to Paige.
You can also play these scenes from the main menu, or you can play them as they occur naturally in the story.
They detail the MC's life before his amnesia year, when he worked at a strip club called Club Aegis, and about his relationship with his first gf, Vespera. They don't progress the main story of the game, but they add background information. Several new characters are introduced, and characters like Lexi and Claire will occasionally appear.