User Interfaces as design Icons
With over 2 billion monthly active users, Facebook is seen millions of times a day in every country. People across the world are continually being exposed to this design language so in many ways it has become iconic. Unlike branding or packaging design, interfaces don't get the same recognition, perhaps because they have a functional role that steals the attention away from the aesthetics; never the less, it's a crafted piece of design that has an emotional and symbolic significance. The same way the patented Coca-Cola contour bottle or the McDonalds' Golden arches are synonymous with their brands, the user interface design of Facebook or Google can now be a crucial part of the brand recognition. This can affect loyalty, user behaviour, the design of competitor UIs and add to the brand's monetary value.
I would firmly argue that the interface itself can become an icon in design history. There are a lot of websites that have changed how we live and work every day. Websites such as Facebook, Twitter, Google and YouTube are seen by billions of people many of which on a daily basis. I use Wikipedia weekly, Facebook on most days and Google and YouTube at least once a day. When I see the core shapes that make up the interface and the icons and fonts, I know which website I am looking at. The recognition is the same as an established logo or a piece of packaging.
UI designs are continually evolving, so it can be hard to ‘record’ them the same way we would photograph a piece of packaging or branding. Facebook is always testing out new features on different groups of users, so your version of Facebook that you see, may not be the same interface that your friend sees. They might be seeing a new icon set or updated colour palette. Facebook regularly makes changes to select peoples interfaces and looks at their behaviour before rolling it out to everyone. So at any given time, you could be amongst the first people in the world to try a particular feature. Because websites are so fluid in design, they are continually evolving making it hard to know what the current design is.