Unlike a layout oriented program, this Page View might in fact not be showing anything related to your print settings at all. First check to make sure it is using “Use Printed Page Size” in the View/Page View sub-menu, and then check the Editor preferences pane to make sure “Printed Page Size” is set to “File > Page Setup Settings”. In most cases this will match the actual output, though it is worth noting that compile settings can have their own page setup settings, too. In other words you could print to 8x11" for proofing, with Cmd-P, but for actual output, compile to 6x9". Whether you want to stare at one or the other while writing is a matter of preference.
Yes, it is compile dependent—indeed some compile formats do not even use pages at all, like e-books and web publishing. But for fixed media output like paper, the compile settings do track the paper setting in the File/Page Setup window by default, but can be switched to use their own paper sizing as well. Hence the page view control gives you the choice between compiled and preferences. Some like to look at something roughly like a page, others just want something that looks nice and don’t really care if the margins are actually one inch wide and so forth.