Filling the frame with a subject can look quite different depending on the focal length of the lens.

These three examples the f/stop stayed the same. I moved the camera forward or backwards to keep the stuffed ducks the same size in the frame.

The 28mm wide-angle lens lets you see the environment around the subject more as you see in this photo of the What the Ducks.

The 105mm short telephoto focal length lens makes the background less distracting.

The 300mm telephoto focal length lens makes the background even less distracting.

Which one do your prefer and why? 

What you need to do is understand how a lens choice can really help your subject.

You just need to say here is the subject then look at using the telephoto lens.  This will help you make the subject pop out away from the background. All the focus will be on the subject.

If you need the subject to be part of a sentence where you use adjectives and adverbs to help give a context for the subject, then move in close with a wide-angle lens. Now you see what is around the subject as well as the subject.

There are varying degrees to this change. Just as the writer uses simple sentences and sometimes longer sentences to tell the story, the lens helps you make it a simple sentence or complex.