what language technique is in brackets:

"he actually watched a bowl of oranges
rise unaided off a sideboard, (as if a clever magician had made his assistant float into the air)"

The language technique in brackets is a simile.

The language technique used in brackets is a simile. It compares the act of watching a bowl of oranges rise unaided off a sideboard to the action of a clever magician making his assistant float into the air.