This mini series focuses on various hidden things throughout the series, from codes at the end of the series to the meaning of the symbols on the cipher wheel. Each episode is roughly five and a half minutes long and each follows the same sort of layout.
Episode 1 is an intro to the series, and briefly discusses Dipper's discovery of Journal 3. The rest of the episode focuses on the opening and ending credits, and things hidden in them, including bigfoot, who can be seen in the opening credits, and the Zodiac at the end of the theme song that contains the cryptogram reading "Stan is not what he seems." The analysis of the ending credits shows the episode 1 credits with the cryptogram reading "Welcome to Gravity Falls."
Episode 2 discusses the episode "Headhunters," and discusses the symbols on the Zodiac. While it has yet to be confirmed, it is pointed out that Mabel's sweater has a llama on it, and a question is posed: could Mabel be both the shooting star and the llama on the Wheel? The cryptogram at the end of the episode is then decoded, and it reads "He's still in the vents."