At the end of the 1st movie, Fiona was wearing a white dress when she and Shrek went on a honeymoon. But in this short movie, she was wearing her green dress.
At the end of the 1st movie, Donkey stayed in the swamp, while Shrek and Fiona went on a honeymoon. But in this short movie, he was with them.
At the end of the 1st movie, the onion carriage didn't make Shrek and Fiona cry. But in this short movie, it made Fiona cry.
When Shrek and Donkey are flying on Dragon they see the princess at 11:00, but Shrek says "Princess, three o'clock".