Continuity mistake: When Dan finally finds DJ under the boardwalk, DJ pulls his hair back behind his ears. After multiple shots his hair is in front and behind his ears.
Ugly Berry - S3-E6
Continuity mistake: Kimmy Keegan gets new Mode business cards and asks Betty what her cards say. Betty says she doesn't have business cards. But in 1-4, "Fey's Sleigh Ride" Betty is given business cards and hands them out at a bar.
Visible crew/equipment: After Wilhelmina tells Marc that she didn't use the dirt he dug up, when Connor walks in Wilhelmina walks toward him, and the reflection of the boom pole/mic is visible on the light fixture. (00:24:30)
The Courtship of Betty's Father - S3-E14
Visible crew/equipment: When Olivia Newton Bird repeats, "I love Connor," in the closeups, the reflection of crew and equipment is visible on the surface of the bowls. (00:21:10)
The Courtship of Betty's Father - S3-E14
Other mistake: When Betty is waiting at Elena's home, Elena walks up carrying a bag filled with groceries, and during their conversation we see the box of Nabisco Thin Crisps and bag of Goya Plantains in the grocery bag. Note the "Nabisco" logo and the brand name have been covered on the box, and there are strips of white tape disguising the brand name "Goya" on the bag. (00:36:10)
There's No Place Like Mode - S3-E15
Visible crew/equipment: After Wilhelmina tells Marc she's wearing Cavalli and not DK, in the next shot as Marc asks, "Are you sure," the pink tape mark is visible on the floor, where Wilhelmina is about to stand. (00:02:25)
Sugar Daddy - S3-E17
Visible crew/equipment: When Amanda brings the baby back to Christina, while she explains that Marc only wanted the baby to hook up with a guy, the orange T-mark is visible on the floor. (00:29:55)
A Mother of a Problem - S3-E18
Visible crew/equipment: After Miles signs the document with Daniel and Wilhelmina, when he tells them, "Au revoir," and leaves, the blue T-mark is visible on the floor under the table. (00:31:30)
Continuity mistake: At the baseball game, when Matt holds out his keycard for Betty the keycard's magnetic stripe is at the top, but it switches to the bottom, then it's back at the top. (00:23:05)
Revealing mistake: After Betty leaves Jodie the voicemail, when Betty looks at Henry's Facebook page with the intention of unfriending him, she moves the cursor to the "remove friend" tab. Then in Betty's closeup we see that tab's reflections on both lenses of her eyeglasses, but the problem is the reflections are not backwards. (00:33:35)