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Yes! You can see it. It is because you are using too many cv.waitkey(0). Meaning, you will see original image's window, then close it. You will see immediately Bounding Rectangle' s window. open Then close Bounding Rectangle' s window.. Then immediately Approx Poly DP's window open. If you want to see all windows on fly, you will have to rem it out 2 waitKey() and leave one at bottom. Code:

#!/usr/bin/env python3
#Raspberry pi 4b, Buster Ver10, OpenCV 4.1.0
#Date: 12th July, 2019

import numpy as np
import cv2

image = cv2.imread('E:\\DOWNLOADS\\Computer Vision\\misc\\house.jpg')
orig_image = image.copy()
cv2.imshow('Original Image', orig_image)
#cv2.waitKey(0)

# Grayscale and Binarize
gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
ret, thresh = cv2.threshold(gray, 127, 255, cv2.THRESH_BINARY_INV)

# Find Contours
contours, hierarchy = cv2.findContours(thresh.copy(), cv2.RETR_LIST, cv2.CHAIN_APPROX_NONE)

# Iterate through each contour
for c in contours:
    x,y,w,h = cv2.boundingRect(c)
    cv2.rectangle(orig_image, (x, y), (x+w, y+h), (255, 0, 255), 2)
    cv2.imshow('Bounding Rectangle', orig_image)
#cv2.waitKey(0)

# Iterate through each contour and compute the approx contour
for c in contours:
    accuracy = 0.03 * cv2.arcLength(c, True)
    approx = cv2.approxPolyDP(c, accuracy, True)
    cv2.drawContours(image, [approx], 0, (255, 255, 0), 2)
    cv2.imshow('Approx Poly DP', image)

cv2.waitKey(0)
cv2.destroyAllWindows()