如何在已经显示在tkinter窗口中的旧图像下显示一段时间后的新图像？

from tkinter import Tk, Canvas, PhotoImage
import time

root = Tk()
canvas = Canvas(root, width=800, height=600)
canvas.pack()

old_image = PhotoImage(file="old_image.png")
canvas.create_image(0, 0, anchor="nw", image=old_image)

root.update()
time.sleep(5)  # 等待5秒钟

new_image = PhotoImage(file="new_image.png")
canvas.create_image(0, 0, anchor="nw", image=new_image)

root.update()

from tkinter import Tk, Canvas, PhotoImage
import time

root = Tk()
canvas = Canvas(root, width=800, height=600)
canvas.pack()

old_image = PhotoImage(file="old_image.png")
canvas.create_image(0, 0, anchor="nw", image=old_image)

root.update()
time.sleep(5)

new_image = PhotoImage(file="new_image.png")
canvas.create_image(0, 0, anchor="nw", image=new_image)

root.update()