Google is testing new AR effects in its Messages app, we have got a video demonstrating the same by XDA developers, you can see them below.
There are 5 camera effects in Android Messages: plane, balloons, fireworks, confetti, and an angel. The feature is present in the camera viewfinder, so when you go to send a picture you can select the effects tab. This is only for sending pictures you take in the Messages app and not in your regular camera. These will send with MMS, SMS, or RCS depending on what your device supports.
Augmented Reality is now being used in so many apps and many messengers, Google is trying to position Android Messages to be more of an iMessage competitor. These new features could bring more users, we will see when this will be released for public. These work very well, they are able to recognize your face and put things in front and behind you with great accuracy. The balloon effect screenshot shows it perfectly. If it were higher quality, you might not even be able to tell if the balloons were fake.