Why was Starlight throwing up at the party in the episode 8 of season 1?
It's implied that she was drunk; we see her speaking a bit slowly, flirting with a random guy and then there's this shot of many empty glasses on her table.
Shortly after this scene she excuses herself to the toilet and starts puking. It's a common depiction in TV / movies that means the character drank too much.
It's also a hook for the trope Book-Ends, since this matches the scene in the first episode where again Starlight and Maeve talk during a vulnerable moment in a toilet.