The purpose of this release is to allow app developers and early adopters to create "even better software experiences". The installation requires flashing a ROM, and if you don't have experience in software development or you expect to use the device as a daily driver, it's not recommended to proceed.
Google notes that Gemini 2.5 Pro Preview (I/O edition) leads the WebDev Arena Leaderboard, a benchmark measuring a model's ability to create aesthetically pleasing and functional web apps.