Continuity mistake: Celeste and Madeline are in the car and greet Bonnie, who's hiking. In the immediate shot of the copilot mirror's reflection Bonnie is nowhere to be seen.
Continuity mistake: Near the end of the episode when Nico is burning the photo of her father, she burns it at the top left corner in a close-up shot. Then in the following shot the photo is suddenly burning at the top right corner instead.