If I look at this instance, for example, https://secure.phabricator.com/diffusion/P/browse/master/, there is a "Pending Differential Revisions" section. When I look at my instance, I see no such section. The URL I'm using (though it's not internet-accessible) is http://phabricator.macprofessionals.lan/diffusion/PPHAB/browse/master/
I'm //pretty sure// there are indeed pending differential revisions for that repo. I can get to it by looking at revisions "waiting on others", then follow the repository link, then click "Browse Repository". The only obvious difference I see is that rP is "Public", while rPPHAB on my instance is visible to "All Users".