Python Tkinter Button Button Button Commande

import tkinter  as tk

root = tk.Tk()
root.geometry("500x300")

"""
Images:
https://drive.google.com/file/d/1tlLl2hjPq38mc_c_PpMhkKDlP1HqvDY5/view
https://drive.google.com/file/d/1bejSlQtIokdQw7d-5Qbqw1X3Sw5Y2bWO/view
"""
# The following 2 'PhotoImage' reads CANNOT be within bellow 'UpdateValue' method
# ( won't read the image into memory quick enough. )
# Option A) use a global variable  
# Option B) create class object ( self.on, self.off ) 
on = tk.PhotoImage(file =  "button_on.png")
off = tk.PhotoImage(file = "button_off.png")
 
def UpdateValue(ar_wid, ar_var,jj):
    if ar_var[jj].get() == '0':
        img = on  
        ar_var[jj].set('1')
    else:
       img = off
       ar_var[jj].set('0') 
    ar_wid[jj].config(image = img)

arr_widgets = []
arr_vars = []
# create 5 toggle buttons
for i in range(5):
    ThisVar = tk.StringVar(master=root, name= f'button_{i}', value='1')
    on_button = tk.Button(root, image = on, bd = 0, textvariable=ThisVar)
    on_button.config(command=  lambda j=i : UpdateValue(arr_widgets, arr_vars, j) )
    on_button.pack(pady = 10)
    arr_widgets.append(on_button)
    arr_vars.append(ThisVar)

root.mainloop()
Thoughtless Tapir