I worked in retail for a couple years after college and I recall the regular changing of sales displays, which were usually prepped in the back room and put into the store in a few short hours.
Here in Italy it works a little different.
With the approach of Christmas shops have been changing their displays and for most of these will consist of one or maybe two windows here in the centro storico. However, to change these display the shops will put paper over the display windows…usually for two or three days, while they meticulously change the display. The paper will appear covering the glass, usually just plain white sheets, and then a day or two later, presto…a new display appears.
Sometimes the paper will appear and not go away, this means the shop has closed for business. We have seen this occur on several occasions.