In my composition class, one of the things I teach my students is how the use of leading lines within an image can strengthen the composition and direct the viewer to the main subject.
In this photo, incorporating the sidewalk pulls the viewer into the composition and creates a more three-dimensional space within a two-dimensional plane. The sidewalk becomes a “leading line” to draw in the viewer to the main subject, San Xavier del Bac Mission, after moving them through the entire composition.
Image copyrighted. Any use requires licensing from Martha Lochert.