There are two methods to change one's external appearance and clothing.
One is transformation.
The other is illusion.
Illusion means deceiving the vision of others, making them believe that one looks a certain way; while transformation is actually becoming that appearance oneself.
And Sun Wukong, he truly transforms.
If Nezha hadn't noticed that this person had been standing in the same spot where Sun Wukong was earlier and had some impression of it, he wouldn't have recognized him as Sun Wukong.
Yet Nezha was puzzled.
How would this allow one to cut in line?
Ah, no.
It was, how could one get to eat tofu cakes ahead of others?
And how did this dragon maiden also turn into an old woman with charm remaining?
The Iron Fan Girl had transformed into a little boy with two pigtails, but her illusion technique was not well practiced, so her face did not change.