Google is rolling out a "feature drop" software update for its Pixel phones, which adds new and improved features to Pixel models going back to the Pixel 2. The Pixel 4 gains improved Call Screen; on-device intelligence will now detect robocalls and keep the phone from ringing at all. Other unknown callers will be screened as before. The Pixel 4 also gains improved Duo video calling. The phone will digitally track and frame your face automatically. It also uses machine learning to automatically fill in small audio gaps when the connection is spotty. A new Google Photos feature lets all Pixel users add portrait effects after a photo is taken, and Duo video calling gains a portrait effect as well. Google is also rolling out certain Pixel 4 features to certain older Pixels, including: Recorder app, Live Caption, Focus Mode, and Flip to Shhh. The update also improves memory management in all Pixel models, allowing more apps to stay open at the same time.