In a preferred embodiment, a display device, including: a front panel and/or a rear panel having defined therethrough at least two apertures; and an index panel(s) disposed behind the front panel and/or the rear panel and moveable between at least first and second positions to vary what can be viewed through the at least two apertures by an observer looking at the front panel and/or the rear panel. In one aspect of the invention, the display device is a book, with the front panel and/or the rear panel being a page(s) of the book and the index wheel(s) being disposed at the front and/or the rear of the book.