I found this in Boots library, this dissertation was written by Katherine Lattaway, she was BA Graphic design student in 2006. this dissertation discussed how art and commerce use in design by retail window display. she chosen fashion field to investigate different designers and artists how to arrange and use their artwork in windows.
in window dressing trade, Katherine has mentioned Dali's. "Dali's intentions to make a new visual statement from within a window continued to inspire those who understood the potential power in display design" so she think although dominate window display design is under threat new technologies, with the development of technology development, expect some retailers go back to use previous methods of window styling, retail window display still can change and evolving. she give a example is Harvey Nichols Christmas window display "outer space" 2005.
this window use the other way to create Christmas scene, to image how alien spend Christmas day in space, rather than use traditional method to express this theme.
and she also got point is "... Ultimately this dissertation will prove that even in the 21st Century, traditional window display serves as both a valuable artistic and commercial commodity."
based on those and my research, in my opinion, expect valuable artistic and commercial commodity used in window display. in this situation which digital product develop rapidly, window display also serve as brand culture value. in doing so, the window of bookstore not only affording vision effect for commercial commodity, but also paying attention brand identity to building relationship with costumers.