A Valve spokesperson has confirmed that Steam's Big Picture mode will be replaced by the Steam Deck UI. Big Picture mode is Steam's version of a console-like user interface: it can be navigated using a controller and was quite loose when Steam Machines was still changing the console landscape (spoiler: no). To say that Big Picture has grown a lot in the tooth is perhaps an understatement, as it has not received a major update. since 2015.
Wondering if the Steam Deck UI will replace Big Picture in the Steam forums, a Valve moderator, austinp_valve, he answered in the affirmative. "Yes, we are replacing Big Picture with the new Deck UI," the message reads. "We don't have an ETA to share yet."
Based on the small views provided, the Steam Deck user interface looks surprisingly superior to Big Picture mode. Once launched, it means that if you want a gaming PC to act as a console, but you don’t want to be defeated on Steam Deck or you’re not interested in portable gaming, you can do so quite easily.
Big Picture mode was released in beta in 2012. If you want to take a look at how the mode looked back in the innocent days of 2012, this exhaustive tour it’s a whole journey. Steam Deck will start shipping in December, if you were lucky enough to make a reservation.