AnkiWeb has no ‘preview’ screen, so I’m not sure what that screenshot is from. I have double checked, and the account associated with the email you are writing from has zero media. Is it possible you are syncing to AnkiWeb using a different email address from the one you used here? If not, and you have confirmed that media syncing is enabled in the preferences, please sync, then go back to the preferences and click on “media log” - what does it say?