TRIANGLE ILLUSION

I SAW THIS  AND ITS 15 FT HIGH.!! BUT SEE IT AND HOW DO YOU THINK ITS DONE..??? I WILL MAKE A SMALLER VERSION..AS YOU CAN NOT CARRY THAT AROUND TO SHOWCASE???? ON PAPER ITS EASY TO DO BUT WITH SOLID TIMBER CAN IT BE DONE YOU DECEIDE????????REMEMBER IF ITS IMPOSSIBLE I WILL DO MY BEST TO MAKE IT POSSIBLE.??!!!