According to the documentation, visual assistants and the Google Home app display graphical interfaces for certain traits without any development work.
https://developers.google.com/actions/smarthome/create#touch-controls
However, I have implemented a smart home action which uses the brightness trait to dim and brighten a users lights. I am succesfully reporting the states of the users devices to Home Graph after the original sync and every execute request but the visual display never seems to update after a successful Execute command.
Has anyone experienced anything similar?