Hi,
the device orientation information is only available in the 'top-most' frame on a web-page.
That means when the viewer is running inside an iframe, it needs to access that 'top-most' frame and get the information from there.
And there the problem - when the iframe is located on an other domain, then the browser is not permitting that access for security reasons - and therefore the Gyro can't work correctly.
Best regards,
Klaus