Facebook Home, a lock screen and launcher replacement for Android, looks very good. In fact, maybe it looks too good.

In the social network’s promo trailer for Home, you first witness a woman picking bright orange pumpkins in a field. A white digital clock typeface contrasts beautifully against the blue sky behind her. An image on Facebook’s Home website shows a woman donning a bright blue life vest paddling through crystal clear waters. Another shows a group of friends climbing a glorious green hilltop. These images are meant to represent stories you might find in your News Feed, which becomes your lock screen if you’re using Facebook Home. You can swipe through them while you’re waiting in line, boarding an airplane, or sitting on the couch. Facebook CEO Mark Zuckerberg estimates we see our lock screen more than 100 times each day.

How does your lock screen look when it’s a stream of oversaturated Instagram photos and out-of-focus baby pictures?

Facebook’s images are stunning, but how does your lock screen look when it’s actually a stream of oversaturated Instagram photos and out-of-focus baby pictures? Or worse? As of this writing, the first thing in my News Feed is an image of a friend who used AMC’s "Dead Yourself" app to mutilate her face — a grotesque sight. The next photo is a group of friends in bikinis on spring break. The third is a friend’s selfie. When you install Facebook Home (or buy an HTC First), your homescreen will be whatever your friends are posting, no matter how good, bad, or downright terrible. When you press the sleep button to unlock your device, these are the kinds of images that will come to life on-screen.

"What if our phones were designed around people, not apps?" Zuckerberg asked, but what if those people are ugly? What if you haven’t seen some of those people in five years? Yes, the News Feed you browse every day is filled with these same things, but your lock screen is the first thing you see in the morning and the last thing you see before you fall asleep.

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Home is undeniably beautiful in its minimalist user interface, but the content it displays cannot ever be held to the same standards, since your friends are producing this content. Some of these friends you may have had since 2004 when Facebook first launched, and some you might not even actually be friends with anymore. That's going to make it hard to be confident handing your phone over to a friend (a real friend, that is) so they can make a quick call. Who knows what they’ll find when they see your homescreen — perhaps they’ll see a wonderful photo of a friend visiting Machu Picchu, or they’ll see the bikini photos from Punta Cana. What if it’s your girlfriend asking to borrow your phone, and your homescreen is somebody else’s cleavage? Halloween-time Home users, beware.

Halloween-time Home users, beware

Just about anything in your Facebook News Feed can become your homescreen, from statuses to photos to links. And "Yep," Zuckerberg said, ads are coming too. While Facebook Home means to put your face (the "bobble," as its called colloquially) front and center, it’s ironic — and, in some situations, troubling — that the rest of your screen is reserved for the photos and statuses of others. Like with Graph Search, Facebook’s issue with Home isn’t in its design, but is in the social graph data that fills it up. Nilay Patel mentioned on The Vergecast yesterday that Home made him want to cut his friends list in half.

As with Graph Search, Facebook says that it plans to constantly tweak the algorithms that populate the pages you’re seeing, and these results will get better over time. "Cover Feed" items are ranked, says Product Manager Adam Mosseri, which means you’re less likely to see photos that don’t have any likes or statuses without comments. Facebook has for years used these metrics to determine what posts are the most interesting, and it has more work to do. If Facebook wants Home to really take off, it needs to realize that we don’t live in a world as beautiful as its marketing campaigns. It could limit "Cover Feed" posts to those only from your closest friends, or it could selectively analyze photos for quality content tagged to popular locations. Until then, I foresee many jokes that start something like this: "Dude, why do you have a salad on your lock screen?"