Emphasis has to do with placement. For this picture, the emphasis is on the light-colored leaf. The light color draws our attention because it's surrounded by dark colors, plus it's placed in the middle of the picture.
This logic can also be applied to writing in that we put what's most important where it will draw the most attention. This is called emphasis. Very often the best placement for the subject is at the beginning because that's where we announce what the sentence is about. For instance, the following sentence is pretty straightforward.
Writers are getting better.
There are times when you want the emphasis at the end of your sentence. The end of the sentence is the climatic stress and where you want to place rhetorical emphasis.
Here's an example...
It must be remembered that writers who study their craft are good and getting better.
So it all depends on where you want the emphasis in your sentence. Which do you like more? Which do you use more often, and why?