How?

Fuck logic, that's how

Maybe they putted it together in the glass.

witchcraft!

Made the glass around the rubics cube? Maybe?

Maybe they deconstructed the cube and put them in one piece at a time.

The bottom is probably open. You can buy those kinds of things for candles.

it's there since the beginning of the universe

Through the bottom

Actually your all wrong. Im the one who did it because of how smart i am, and none of you shall know how either

Ship in a bottle style I guess