What is the reason behind putting the top sheet reverse on the bed?

grandmother,mom,sister does itWhat is the reason behind putting the top sheet reverse on the bed?
so when you pull the sheets back ( to make the bed pretty) they show up the right way. I do it too..What is the reason behind putting the top sheet reverse on the bed?
if you have ';thick edged'; sheets, more than likely it's for comfort. Most flat sheets have a 2'; double layered edge with is generally the ';top'; of the sheet, and that goes to the head of the bed. If you don't want that 2'; band of thickness weather due to heat, or feel, that's called reverse sheeting where there is a ';standard hem'; at the neck and double hem at the foot of the bed. For people that ';long sheet';, reverse sheeting is not overly common, however it does present a more uniform appearance and is often used by inns attempting to acheive a low cost clean appearance.
Because when you fold the top sheet down, the design is showing instead of the underside of the sheet.