Your app’s Play Store listing provided a non-valid Wear OS screenshot which is framed within the device. A valid Wear OS screenshot must include the full-frame image of the app interface.
To those who have successfully rolled out a Wear OS app, would you please tell me what Google is trying to say. Thanks!
Edit: I have taken Yuri's advise have uploaded the 384px by 384px image below for the Wear OS section and created another release. Now, I'm just waiting for Google's feedback. Thanks, Yuri
Second Edit: The image above fixed my issue.