https://www.reddit.com/r/learnpython/comments/aumrmg/tkinter_displaying_an_image_in_a_canvas/

main.py

import tkinter as tk
import tkinter.filedialog as filedialog
# from pillow import Image, ImageTk


class ImageLayer:
    def __init__(self):
        self.width = 0
        self.height = 0
        self.x = 0
        self.y = 0
        self.path = ""
        self.img = None


class LayeredImageBuilderGUI(tk.Frame): # HERE
    def __init__(self, master):
        super(LayeredImageBuilderGUI, self).__init__(master)
        self.pack()
        self.master = master
        self.canvas = tk.Canvas(self, width=1024, height=768)
        self.canvas.pack(expand=True, fill=tk.BOTH)
        self.master.bind('<Button-3>', self.display_contextual)
        
        self.init_contextual()
        self.images = []
        self.photoimg_objs = []
        # self.loop() # HERE

    def init_contextual(self):
        self.contextual_menu = tk.Menu(self, tearoff=0)
        self.contextual_menu.add_command(label='Add Image',
                                         command=self.add_image)

    def display_contextual(self, event):
        try:
            self.contextual_menu.tk_popup(event.x_root, event.y_root, 0)
        except Exception:
            pass
        finally:
            # make sure to release the grab (Tk 8.0a1 only)
            self.contextual_menu.grab_release()

    def add_image(self):
        img_path = filedialog.askopenfilename()
        im = tk.PhotoImage(file=img_path)
        self.photoimg_objs.append(im) # HERE
        layer = ImageLayer()
        layer.width = im.width()
        layer.height = im.height()
        layer.path = img_path
        layer.img = self.canvas.create_image(0, 0, image=im, anchor="nw")
        print(layer.img)
        self.images.append(layer)
        # return

    # def loop(self):
    #     self.canvas.update_idletasks()
    #     self.after(5, self.loop)


if __name__ == '__main__':
    root = tk.Tk() # HERE
    LayeredImageBuilderGUI(master=root) # HERE
    root.mainloop() # HERE