What did thomas see when he went through the changing in The Maze Runner?

Thomas, in the book and movie *The Maze Runner*, doesn't actually go through a "changing." The term "changing" in the story refers to the process where the Gladers, the boys trapped in the Maze, go through a physical and mental transformation after spending time in the Maze. It's a process that's not fully explained and has no direct connection to Thomas's entrance into the Glade.

When Thomas arrives in the Glade, he has no memory of his past. He's brought up through a metal box called the "crate" along with a note that reads, "Welcome to the Glade." He wakes up with a confused mind and is introduced to the new world he's found himself in.

So, there's no specific event or sight that Thomas sees during a "changing" because he doesn't go through one. He's simply brought into the Glade and has to learn about his new surroundings and the people he's with.