When you look at two choices and can't tell immediately which one you want, the choices don't matter.

I love facebook. They have a great design aesthetic. Overall, the new design is awesome. I like how it opens the page up, and I think it'll do wonders for their ads.

OK, that being said, can someone please tell me why this UI exists?

Unfortunately it's the equivalent of the Vista Shutdown bar -- don't give me these options. One-line, small, large? I do not care how big this story is. I care about my post and my friends' comments and that's it. Every choice you give the user is a decision they have to waste precious brain cycles on.

Paul Graham from YCombinator says that when you look at two choices and can't tell immediately which one you want, it's either that the two choices are too similar, or they don't matter... or most likely, BOTH. This applies perfectly in the UI shown here. As Sachin and I work on Posterous, one of the most important things we can do as designers and engineers is to make sure we actually take away choices that don't matter. We internally talk about how we want to be the Apple of blogging. How do we do it? Just make a decision and move on. We hate preference panels.

Be opinionated, as 37signals so aptly notes. And I quote: "The best software has a vision. The best software takes sides. When someone uses software, they're not just looking for features, they're looking for an approach. They're looking for a vision. Decide what your vision is and run with it."

Meta-aside:
It's such a trip to be giving product feedback on another product now that I see the emotional impact of feedback on the creators of whatever feature. On the one hand, it makes me want to lighten how strongly I deliver my feedback since creating user experience really is quite an emotional process. You can't even make decisions without emotions (they've done studies on this!), so really whenever someone challenges a design decision you've made, you're really just thrust into the same tumult of choice that forged the decision in the first place. On the other hand, harsh feedback is the only feedback that matters.

Got something to say about posterous? Would love to hear it -- garry [at] posterous dot com