One of the new features we're getting to see in Android 11 is Bubbles, a new experience for messaging that will implement chat heads at the system level. It only works with a few apps now, such as Facebook Messenger and Google's own Messages app, but a new APK teardown shows that the Google Assistant may be working on a chat head bubble of its own.
According to a teardown of version 11.21 of the Google app beta, it looks like work is underway on a method to access the Assistant through the Bubbles API introduced in Android 11. When enabled, the Assistant logo appears in a white bubble floating above other content. Tapping it opens up the standard Assistant interface, although that's probably just because it's a work in progress.
<string name=”opa_chat_head_tutorial”>”Tap to talk to your Assistant.\nDrag to move or dismiss.”</string>
Text strings in the beta refer to the feature as "Assistant Chat Head"
Currently, there are a lot of ways to trigger the Assistant: swiping from the bottom corners of the screen, saying the hotword, tapping the icon on the Google search widget, or even just squeezing an Active Edge equipped phone. I guess the more ways the merrier? Google has made it clear that Bubbles are only intended for conversations right now, but I guess I can see the argument that chatting with the Assistant is a kind of conversation.