Exercise
Choose a subject in front of a background with depth. Select your shortest focal length and take a close low viewpoint, below your subject. Find a natural point of focus and take the shot.
Result
In this image, the wide angle has created a perspective that causes the subject to appear far larger in relation to its surroundings than it actually is. The stump is large, but to a naked eye, it does not fill the whole field of view as it does in this image. In addition, the space behind the subject is considerably extended; it looks like there is quite a gap behind the stump when there is not. Part of this extension may be a trick of the mind, if the stump really were as big as in the image, then the spaces behind it would have to be vast to be in the proportion that it looks in the picture.
Note: The light when I took this images was quite dim and a narrow aperture was required to be able to at least see the surroundings if not have them pin sharp. Unfortunately as I was hand holding the camera, this meant I needed to have quite a high ISO, higher than I would have liked and therefore there is an element of noice in the picture.
Learning Point
This effect as with others needs to be understood so that it can be avoided or included as desired. As a technique it could be used to emphasise a particular part or segment of a subject within a wider context.