Continuity mistake: When Shrek backs into the two barrels at the tournament, they both have taps on them. He then bashes one of these off with the beer mug. But when Donkey rolls the other barrel the tap has vanished on that one as well. (00:24:00)
Continuity mistake: When Chihiro talks to Kamaji about taking the train to see Zeniba, she says "Yep, I'll walk back along the tracks," and turns around, and the little mouse and bird are sitting on her left shoulder. It then cuts to a wideshot of Chihro walking over to Haku, but now the mouse and little bird have vanished from her shoulder. (01:27:15)
Other mistake: In the scaring simulation room, the alphabet wallpaper border at the top of the wall has the "J" written backwards.
Suggested correction: The walls of the room also have nonsensical drawings like a giraffe with two heads. The implication is that the monsters designing the room didn't entirely know what kids would actually have in rooms (like they didn't know that giraffes don't actually have two heads). So they thought that humans have the J backwards.
Whether or not the backwards J was intentional or as a joke, it would still seem unreasonable for the monsters to get it wrong when you see they got the pictures for each letter seen correct "jaguar", "kangaroo "pig", "quail", "rhino." I would at the very least call it a character mistake.
As the original correction said, it's just an example of the monsters not understanding the human world. Not a mistake.
Yet they know the alphabet? I doubt it.
Continuity mistake: In the recap of the shot where Ash puts on his right glove, he puts it on differently in the movie than in the episode where this takes place. Also, the shot on the television set is an upward-looking corner view, but in the episode, it is a straight-looking side view. Additionally, Gengar is moving, but it was not in the episode. Furthermore, the controls for the volume and another one do have symbols, but in the episode, they did not. Moreover, a curtain is draped over the right side of a window with Ash not having it behind him, but in the episode, the curtain was not draped over there with Ash having it behind him. (00:01:34)
Continuity mistake: When Jimmy and the rest of the kids are standing on the balcony, Jimmy asks Goddard to activate his binoscope so they can get a better view of the arena. Goddard then extends his eyes into tubes and raises them. However, in the next shot, his eyes are raised but not extended into tubes yet. They also take on a different shape than in the previous shot. (01:04:53)