>>4381438This guy
>>4381440 explains it almost better than I do. Ultimately, distance to the subject creates "telephoto compression" (see article).
https://petapixel.com/is-lens-compression-fact-or-fiction/This stuff is hard to explain on paper but easier in practice. You don't even really need a zoom lens (tho it can make the exercise easier). You can take photographs of yourself at various distances from the camera and crop in so that your face fills the frame. You'll find the further back you get (to a limit), your features will be more "flat". A longer lens will allow you to do this without needing to crop.
