how to load an image to a new window in tkinter

Question

Hi I have a problem with loading an image to a new window in tkinter. Here is my code to open new widnow and it opens new window, but it doesn't open a new image. I can load images to my root window without problem as you can see below, but I also need to load a new/another image to a new window.

def open_new_image(self):
    new_image_window = Toplevel(self.root)
    new_image_window.title('New window')
    new_image_window.geometry("700x500")
    lbl2 = Label(new_image_window)
    lbl2.pack()

    def onClick():
        img = self.load_image_internal()
        # new_image = ImageTk.PhotoImage(Image.open(path))
        lbl2.configure(image=img)
        print("dsdsds")
        new_image_window.update()

    load_image = tk.Button(new_image_window, text='Load image',
                                command=onClick)
    load_image.pack()
    new_image_window.mainloop()

Here is my method for loading an image

def load_image_internal(self):
    path = os.getcwd ()
    filename = filedialog.askopenfilename(initialdir=path,
                                           title="Select image",
                                           filetypes=[
                                               ("image", ".png"),
                                               ("image", ".jpg"),

                                           ])
    return ImageTk.PhotoImage(Image.open(filename))

I have no idea why it doesn't work. I have tried to look for answer here, but all replies are for loading image to the main/root window which I already have.

I have tried, but I am stuck how to make the load image button work.