Quick saddle question. (bare with me I'm a newbie to touring)

I was wondering about the function of the side apron on a saddle. I see most people who tour tend to have the side aprons where racing saddles do not. Is it strictly visual, a product quality thing or is there a function to it?

I recently put the velo orange model 6 (no aprons) on my bike. I choose it over the model 3 (with aprons) because even on long rides I seem to prefer a slightly narrower saddle (20mm difference) and I felt the look of it better suited my taste. The thought never occurred to me till looking more at photos on this site that the aprons may have a significant purpose.