Ошибка "Exception in Tkinter callback"

Exception in Tkinter callback
Traceback (most recent call last):
  File "C:\Users\R\AppData\Local\Programs\Python\Python310\lib\tkinter\__init__.py", line 1921, in __call__
    return self.func(*args)
  File "C:\Users\R\YandexDisk\pythonProject\pdfinsert\neww\towwindows.py", line 17, in new_window
    Window().mainloop()
  File "C:\Users\R\YandexDisk\pythonProject\pdfinsert\neww\towwindows.py", line 25, in __init__
    label = Label(self, text='Second Window', image=self.img)
  File "C:\Users\R\AppData\Local\Programs\Python\Python310\lib\tkinter\__init__.py", line 3177, in __init__
    Widget.__init__(self, master, 'label', cnf, kw)
  File "C:\Users\R\AppData\Local\Programs\Python\Python310\lib\tkinter\__init__.py", line 2601, in __init__
    self.tk.call(
_tkinter.TclError: image "pyimage2" doesn't exist

from tkinter import Tk, Label, Button
from PIL import Image, ImageTk
 
class MainApp(Tk):
    def __init__(self, *arg, **kwarg):
        super().__init__(*arg, **kwarg)
 
        self.img = ImageTk.PhotoImage(Image.open('famous-joke.png'))
 
        label = Label(self, text='First Window', image=self.img)
        button = Button(self, text='Open Window', command=self.new_window)
 
        label.pack(side="bottom", fill="both", expand="yes")
        button.pack()
 
    def new_window(self):
        Window().mainloop()
 
 
class Window(Tk):
    def __init__(self, *arg, **kwarg):
        super().__init__(*arg, **kwarg)
        self.img = ImageTk.PhotoImage(Image.open('famous-joke.png'))
 
        label = Label(self, text='Second Window', image=self.img)
        label.pack(side="bottom", fill="both", expand="yes")
 
 
if __name__ == '__main__':
    MainApp().mainloop()