It is not possible for the program that launched the preview, or the programmer who wrote the program, to know how the user wants to deal with the preview: display the preview windows right now, or continue working and view the report later? The Preview Window State allows the user to set her preference for what happens when a report is sent to the preview window. "Visible (Foreground)" means that the preview window is shown right now. "Minimized (Background)" means that the preview window is created right now but then minimized; it appears in the task bar, which you need to click in order to view the report.