It looks like your screen is not rotating when you rotate the tablet. It could be a problem with the Accelerometer which senses when the tablet is rotated.
- Have you tried removing the rotation lock in settings in Android?
- Is this a dual boot tablet? If it is boot into windows and see if the screen rotates when you rotate the tablet. If it does then the problem is in Android. If it does not, then the Accelerometer is not working.
HTH