Instagram follower's recent photo not showing up?

So I'm only following one person on Instagram and they're following me, and today they posted a pic that I didn't see for 11 hours. We're still following each other and I can still access their pictures, but when I logged in from another computer their most recent photo showed up that I couldn't see in my iPhone 5 app. After I saw it from the other computer, I logged into Google with that same computer and then it showed up on their Instagram feed on my phone. So now everything is uniform but I didn't see the pic for several hours until after it was posted (according to the time stamp in the top right hand corner of the Instagram photo, which says "11hrs", "1w", etc.)

Is this a glitch in Instagram or are there some privacy settings that can restrict viewers? I've searched Instagram's website and Google and found nothing that would indicate a customization of who views what on Instagram (aside from blocking, which I don't think has happened since we still follow each other and I can still see their pics.

Is there some app on the iPad or iPhone that can do this or was Instagram just lagging? Anyone else had this experience?

Added (1). When I say "everything is uniform" I mean that I can see the pic on both the computer and my iPhone, but it didn't happen until after I saw it on the computer and then logged into Google on that computer and rechecked it.

Added (2). *I actually did update my app on Jan 1st 2014.

That happened to me once, go to app world and update your instagram app. That should fix it.