I’ll do better than that. Here’s a series as would be taken with a 20mm shift lens, shifted horizontally, and vertically to all possible extremes…
And here is the image taken with a standard 20mm lens…
In all shots, the sensor is in the same position, therefore all images are taken from exactly the same perspective, it’s just that shifting the lens changes which part of the overall image gets recorded.
Your examples are invalid for comparison because you are moving the camera and not just the front of the lens.
Moving the camera changes perspective, which is why you see more of the top of your hydrant.
Shifting the lens does not change the perspective, it just changes the framing.
Watch this excellent video, which shows shifting in action…
Take particular note of what happens to the proportions as the lens is shifted. The further it is shifted out from the centre, the more you see the “wide angle effect”. This is because the shift lens is essentially a very wide angle lens, which is panning around the image circle.