> "We do not offer the ability to upload from the web as Instagram is about producing photos on the go, in the real world, in realtime. On the other hand, Instagram for the web is focused on making the browsing experience a fast, simple and enjoyable one."

I think that's a key part of the article. While I do understand their current vision to keep Instagram mobile upload only, I do wonder if that plan ever gets changed by a business decision with Facebook. I suppose time will tell if they can stick true to this or not.

As @NathanKP said, it is interesting to see some photo filters feel much more grainy on the web than they do on my iPhone.