Continuity mistake: After Ozma unstraps Dorothy from the pedestal, they run from the room, leaving both of the double swing-doors wide open. In the next shot of Dorothy and Ozma running down the hallway though, the left door is closed. (00:18:40)
Continuity mistake: When Dorothy looks up and spots the head of the 'Gump' on the wall, it is covered with cobwebs. Later when Jack removes it for the couch, it is clean. (00:48:20 - 00:50:50)
Continuity mistake: When Dorothy unties the red key from Mombi's wrist, while she is asleep, Mombi then snores and rolls over, and the red key lays on the bed. The position of the black ribbons attached to the key repeatedly changes between subsequent shots. (00:51:20)
Continuity mistake: When the Wheelers have arrived back to Mombi's castle, in one shot you can see a broken pillar next to one Wheeler, totally bare. In the next overhead shot a long vine of ivy is laying on it. (01:09:20)
Continuity mistake: When Dorothy finds the small green glass ornament, she shouts "Oz!", and the Scarecrow appears. In the shot when Dorothy calls "Oz", there are two large ornaments to the right side of the counter. Then when it cuts and the scarecrow "appears", the ornaments have now moved a few feet away, so that the Scarecrow can comfortably "appear." (01:23:55)
Continuity mistake: When Dorothy finds Tik Tok, there are cobwebs that hang from the wall beside him, and are draped on the side of Tik Tok's metal helmet. However in some shots these cobwebs that hang on his helmet vanish, then reappear again.
Continuity mistake: When Tik Tok takes the lunch pail from Dorothy, to use it to attack the Wheeler's, his arm is naturally shiny. Moments later the same arm suddenly has cobwebs all over it. Then when Tik-Tok gets to the end of the corridor, the cobwebs are gone again.
Continuity mistake: When Dorothy picks up the key that she thinks was sent from Oz, she begins to rub the dirt off of it, getting her fingers dirty. In the next shot they're clean. In addition, the way she holds the key changes between shots.
Continuity mistake: When Dorothy is sent back to Kansas, she wakes up in the forest and she has a large spot of dirt on her forehead. This vanishes when Toto runs to her. It then reappears later, but now on the side of her forehead.
Continuity mistake: When Tik Tok is just about to swing the lunch pail into Mombi, he freezes because his action winds out. In the next shot his position (his left arm, and the angle and way that he holds the lunch pail) changes between shots.
Continuity mistake: When the Doctor is setting up the machine for Dorothy, the power then goes out. Everyone leaves. If you look at the machine, it's 'tounge' is on the right side of it's 'mouth.' In the next shot it is now on the left, and it then stays there.
Continuity mistake: When Dorothy and Billina stand in the crate, after the storm, trying to figure out where they are, in overhead wideshots of them standing in the crate, Dorothy's dress rustles in a breeze, but in closeups of her, it is perfectly still.
Continuity mistake: When it shows Dorothy eating her Limestone cake with Tik Tok and Jack, in one shot her goblet of melted silver is rested, down on the table, but then suddenly in the next shot it is in her hand, off of the table.
Continuity mistake: Aunt Em opens Dorothy's bedroom door a crack to check on her. She is standing outside the room, but she is peeping through the crack. Dorothy looks at her, and suddenly Aunt Em is standing in the room with the door almost fully opened.
Continuity mistake: After Dorothy winds Tik Tok up (after he had gone beserk) her pigtails alternate from what shoulder they hang over (ie. her right pigtail was hanging behind her shoulder in the first shot, but then hangs in front of it in the next shot.)
Continuity mistake: When The Nome King shows his ruby slippers to Dorothy, and tells her that he could send her back to Kansas, in frontal shots both his feet are down on the floor, but in shots from behind he is wiggling his right foot up in the air.
Continuity mistake: On The Nome King's mountain, everyone looks up, and Tik-Tok is standing closest to the edge, then the sofa-body of the Gump is there, then Dorothy on the other side of it. In the next shot Tik-Tok is suddenly beside Dorothy.
Continuity mistake: When it shows the chickens on the farm, just before Toto runs over and scares them all, the position of the brood of chickens is completely different between shots, and the branches and logs around them have also changed around.
Continuity mistake: When the group lands on The Nome King's mountain, we see Tik Tok land with his body buried in the snow. Then in the next shot he is suddenly less buried than he was in the first shot. Then in the next shot he isn't even buried, and is just laying on a rock.
Continuity mistake: When Dorothy and Billina are in the crate surrounded by water, then water begins to soak up, so that it gets very shallow. In the next shot over Dorothy's shoulder the water is suddenly more deep and rippling again. Also, the sand, once it dries up, goes from damp to drier.
Answer: She was in the human world so she was in disguise.