The island is glued to the back glass of the tank. At first I assumed it was floating with styrofoam and thread anchoring it down. I read about it in an interview with the creater of that tank.
The pics were from different years of TFH magazine. The article explained why each tank received the score that it did. I believe you can buy backissues of TFH at least in digital form if you want more information.
I know the owner of this tank... it belongs to a store here in HK... was an absolutely amazing setup, shame he sold it to a hotel i think 1 or 2 years ago now... hes re-scaped the tank, although as he says, still needs a lot of work before he'll be entering more competitions this year for the large tank category...
To me it is insane how they can make tanks look like this. It would probably take me years to even have one look half as nice as some of these.. Granted I have never had a planted tank though..