New this month Revealing mistake: When Emma leaves the apartment to go looking for Ashley, she and Henry walk down the streets of Storybrooke, toward Emma's car. As Emma says, "Because I know", in the background, you can see a business called Steveston WineMakers. Steveston is the name of the Canadian town which doubles as the town of Storybrooke on Once Upon a Time.
New this month Revealing mistake: Ruth has gray, curly hair. When Bo Peep bangs the shepherd's crook on the ground, sending Ruth and David flying to the ground, in the shot from behind them, Ruth's hair is much smoother; the one falling is obviously Gabrielle Rose's stunt double.
Visible crew/equipment: When the horse carriage is ambushed, just as Princess Abigail can be heard screaming "Please, help me", the camera pans downward and a horse wrangler wearing a blue baseball cap can be seen in the lower left hand corner, hiding behind one of the horses.
Revealing mistake: After the scene with Emma and Henry at the playground, there is a wide shot of Storybrooke Main Street. As the camera pans down, in the upper right hand corner, you can see the clock tower, but without the top two stories (the top two layers of the clock tower, including the clock, are CGI).
Deliberate mistake: Elsa's dress in Season Four is different from the dress she was wearing in the Season Three finale. The new dress is a different shade of blue, and has a completely different design, even though the present day events of Season Four take place mere moments after the end of Season Three.
Revealing mistake: When Sheriff Graham pulls in front of Emma in a police car, the big sign on the storefront behind Emma says "Storybrooke Coffee Co." However, as Graham gets out of the car, you can see a circular sign on the side of the building, which says "Steveston Coffee Co"; Steveston is the Canadian town which doubles as the backdrop for the town of Storybrooke on Once Upon a Time.
Continuity mistake: Emma has a flower tattoo on her left wrist. Throughout the series, there are subtle changes in its design, and its position on her arm. For example, when Emma is sitting at the table with Mary Margaret in "The Thing You Love Most", the tattoo has six petals, and is located about an inch below her hand. When she's on the phone with Ruby in "Red-Handed", the tattoo is much bigger, and the petals are arranged differently; it has also moved further up her arm, and is almost touching her hand. When she's arrested in "Tallahassee", there are five petals instead of six, the petals have a rounder shape (in "Red-Handed", they were rather pointy), and the tip of one of the petals is touching her hand. When she pulls her hair behind her ears at the tavern in "Snow Drifts", said petal is thinner, and is no longer touching her hand.
Character mistake: In the evening, Emma states that Kathryn Nolan has been missing for 24 hours, meaning that this episode takes place the day after Kathryn disappeared. When Emma investigates Kathryn's car, David tells Emma that he last spoke to Kathryn "yesterday afternoon" (and stresses that he is telling the truth), and that he hasn't spoken to her since he ended their relationship. However, "What Happened to Frederick" establishes that David broke up with Kathryn the day before she tried to leave town and disappeared, because when Kathryn apologized to Regina, Regina referred to the events surrounding the break-up as "what happened yesterday." Emma checks Kathryn's phone records and finds out that Kathryn talked to David on the phone the day she disappeared, but David could not have referred to that conversation, since "Red-Handed" and "Heart of Darkness" both establish that he doesn't remember the phone call because of a memory blackout. While it is possible that David could have been referring to a second, off-screen, break-up conversation with Kathryn the day she disappeared, when Sidney shows up with the phone records, Emma specifically says to him that David told her that he DIDN'T speak to Kathryn that day, which, in fact, he said he did.
Continuity mistake: When Regina is standing in front of Rumpelstiltskin's mirror at the end of the episode, as he asks, "What are you gonna do now, then?", the cloth that was used to cover the mirror is lying on the floor. When he transforms her back to her normal form, it is gone.
Revealing mistake: When Emma walks Henry to school, as Emma says "Because I'm the daughter of Snow White and Prince Charming?", a reflection of the clock tower building is visible in the window behind her, only there's no clock (the top two layers of the clock tower, including the clock, are visual effects).
Revealing mistake: After Ariel stabs the Evil Queen in the neck with a fork, Ariel and Snow White jump into the ocean to swim away. In the underwater shot, you can see that the ones swimming through the water are not Ginnifer Goodwin and JoAnna Garcia Swisher, but their stunt doubles.
Continuity mistake: At the end of the episode, the hands on the clock tower move forward for the first time. In the wide shots, the circle surrounding the clock, as well as the wooden beams forming the outer edges of the area around the clock face, are white. In the close-up where the minute hand moves, the circle and edges are brown. Also, in the wide shots, the area around the clock face of the building is shaped like a square, but in the close-up, it is in the shape of a trapezoid. The same thing happens when the clock moves in "The Thing You Love Most" and "A Land Without Magic."
Continuity mistake: The blade on the Dark One's Dagger has one side with the name of the Dark One inscribed, while the other side is decorated with a pattern. The name keeps switching from one side of the blade to the other, throughout the series. In some scenes, the writing is right side up when the dagger is held in the left hand and facing the wielder: This happens, for example, when Rumplestiltskin finds the dagger in "Desperate Souls", when Mr. Gold gives the knife to August in "The Return", when Gold summons the wraith in "Broken", when Cora has the dagger in "The Miller's Daughter", when Zelena controls Mr. Gold in "The Tower", and when Gold triumphantly shows the dagger to Zelena in "Kansas." In other scenes, the characters are right side up when the dagger is facing the wielder and held in the right hand: For example, when Rumplestiltskin summons Zoso in "Desperate Souls", when Cora steals the knife in "The Queen Is Dead", when Gold uses the dagger in "Going Home", when Regina picks it up in "Kansas", and when Gold hides the dagger in "Snow Drifts."