Continuity mistake: After Gus and Jack bring the key to Cinderella, Lucifer puts a bowl on top of the key. His paws swap from holding the upper part of the bowl to the middle part between shots.
Continuity mistake: When Jack and Gus arrive at Cinderella's room carrying the key, the key turns 180ยบ around between shots.
Continuity mistake: Right before we see Cinderella for the first time, the nest on the upper left side of her window suddenly appears between shots.
Continuity mistake: When the sisters order Cinderella to iron their dresses, the amount of stuff on the floor is not consistent with the first shots and the stuff that the sisters later throw.
Continuity mistake: When the mice open a small door and see Cinderella holding all the clothes and being scorned by the sisters, the little door keeps changing colours between shots: From solid pink to grey, to wood-grain texture.
Continuity mistake: Before the animals start to sew Cinderella's dress Jack says "Cinderella might not go to the ball", then a mouse sitting on the edge of a spool of thread with a needle showing behind her cries "What?" The shot changes and she's now sitting on the center of the spool and the needle is nowhere to be seen. This changes back and forth depending on the angle.
Continuity mistake: Cinderella places her mother's sewing book with the binding standing on the edge of the right side of the trunk. A shot later the book has moved 15 cm to the left.
Continuity mistake: When Cinderella dances with her mother's dress check the basket on the floor: the spool of thread on the floor and the scissors inside the basket suddenly appear between shots.
Continuity mistake: When Cinderella takes her dress out of the trunk the mice aren't there. A shot later they magically appear, standing on the lid.
Continuity mistake: When the birds throw the sponge into the basin, in the closeup shot the basin's edge has a simple style, as opposed to the ornamented one in the wide angles.
Continuity mistake: After the stepsisters destroy Cinderella's dress and she runs away, all the rags on the floor disappear in the aerial angle. They're not offscreen: Check the pattern of the floor and the column behind. Also, the object on the table behind her disappears too.
Continuity mistake: Jack tells Cinderella that there's a new guest and she picks a yellow jacket, a blue piece of fabric and a pair of shoes. In the following shot the shoes disappear from her hand, and a shot later the jacket and the fabric also vanish.
Continuity mistake: After she wakes up, Cinderella walks behind the screen and a girl-mouse commands the others to get inside a plank. The girl-mouse stands in front of the gap between two planks. A shot later she's now behind the gap.
Continuity mistake: Cinderella wakes up to the clock's chime and pushes the duvet to the foot part of the bed. In the following shot the way it's folded changes, and a shot later it's now magically covering almost all of the bed.
Continuity mistake: After Cinderella picks up her dress from the trunk the mice standing on the lid change positions: From purple, yellow, blue and red, to light red, yellow and turquoise blue. Change of colour of the dresses might be due to lighting.
Answer: Cinderella's entire outfit was magically created by the Fairy Godmother. Not only was the spare shoe Cinderella had in her possession identical to the other one, it likely would be charmed so that she is the only one who can wear it. It's similar to young Arthur being the only person who could pull Excalibur from the stone because he was the true king. No other woman who attended the ball wore glass slippers. If they had, they'd be able to also produce the spare shoe as proof.
raywest ★