Lens compression

Step back, zoom in, and the background appears to close up behind your subject. Strictly it is the change in camera-to-subject distance doing that work rather than the glass itself, but the effect is real and it is why an 85mm portrait looks better than a 24mm one shot from a metre away. A wide lens up close stretches whatever is nearest the camera, which on a talking head means the nose. For a desk setup, sitting further back with a longer lens gives you a flattering face and a background that blurs into shape and colour instead of clutter.