The first screenshots of the Steam Deck interface, as well as SteamOS 3, have been leaked.
According to SteamDB's developer, the operating system (OS) of the Steam Deck development kit has been leaked. We now have new photographs of Valve's laptop user interface, thanks in part to this. 

The Steam Deck Dev Kit was sent out to developers earlier this week, but something unexpected happened. This kit has been leaked, according to Pavel Djundik, founder of SteamDB, with which we have been able to observe SteamOS 3 and photographs of its user interface. As a result, some Valve features that were supposed to be disclosed with the Steam Deck have leaked ahead of time. For instance, the operating system that they intended to include in their laptop and the interface that we will use to access Steam features and games.The Steam Deck OS will be SteamOS 3.0, a new Linux-based version that looks and feels like the Windows app. According to Djundik on Twitter, the OS has been released and can be used on various devices, signalling a departure from the original SteamOS in favour of something more Valve-like.

Djundik hasn't mentioned the SteamOS 3 systems, but it's safe to presume they're portable PCs running GPD Win 3 and Aya Neo. Pavel demonstrated a portion of the Steam Deck user interface, which many will recognise as Steam.

For a few weeks, there was a rumour that this Steam Deck interface will be utilised to replace the already-outdated Big Picture option. Despite the fact that the photographs he released on Twitter do not reveal anything new to regular Steam users. Of course, they're there to give you an idea of what you'll get when you use Steam Deck, but bear in mind that this interface is still being worked on. Because it is still subject to change, it is likely that there will be changes in the coming months. "Steam Deck's user interface is essentially a modified library on a computer. Currently, there is no option to go into the store "remarked in the tweet

In other developments, AMD is collaborating with Valve to make the laptop compatible with Windows 11, with the goal of resolving the TPM 2.0 requirement, which is a flaw in that version. What I'd fix is its compatibility with the operating system and future releases. Valve intends to release the Steam Deck before the end of the year, however, some customers may have to wait until the second quarter of 2022 or later.