This setting switches the default behaviour of the arrow links. By default (well, by default in iTunes 10.0.0 and before) the arrows would send the user to the corresponding page in the iTunes Store, but you could also hold down Opt and click to be redirected to the corresponding list in your own library. In my opinion, this was an incredibly useful feature: you can navigate through your own library so quickly. The "invertStoreLinks" setting makes this the default, so you just click to navigate. Holding down Opt while clicking will take you to the store.
Apple, 100% dédié à l'intuitivité.