This exercise was to compare the effects of how your physical viewpoint needs to change when shooting with different lenses.
Using a 105mm lens , the focal length at the extreme of my zoom lens, I took this first picture.
As can be seen the building is slightly flattened in perspective and fits into the portrait format neatly. I then moved to the other setting on my lens, 24mm. Immediately the way the subject fitted into the frame changed.
Following the instructions I walked forward watching the image change in the viewfinder until I was in a position where, if I squatted down slightly and tilted the camera I could again fill the frame with the subject.
As can be seen the perspective has changed quite dramatically in comparison to the first shot and the exposure, although at the same aperture and speed, differs.
Due to changes in the angle of view between the two focal lengths it does create clear differences in how the subject can be framed and the end result. Telephoto images have a "compressed" feeling where actual depth of field is narrower and the distance between sepearet objects appears closer than it actually is.
At the other end of the range the "expanded" perspective of a wide-angle gets further distorted by the increased depth of field and the actual curvature of the lens , so close up images become distorted and the feeling of a converging perspective increases in the portrait format.Also objects in the image show more perceived space between them that can be seen in the same shot taken with a "longer" focal length.