Ingenious and amazing!
It's two tricks in one....
The magician shows to the audience a cube and a silk.
He squeezes the silk into his hand, the square goes into his pocket.
Amazingly, the cube is in his hand (instead of the silk) and the silk comes out from his pocket!
Or if you prefer....
The magician shows that he has a silk in his hands and stuffs it into his fist. Now comes the surprise - the silk has changed into a colored cube!
Everything can immediately be examined in both routines!