Why this trick?
We know how problematic tricks where you need to switch a deck, a case, or another object can be. So this effect was designed to be taken from the pocket and performed in full view, without having to ring in a gimmick, a phone, or place anything in the pocket to be switched.
The phone looks like most phones these days, in size and black screen appearance. It is, in fact, the most copied style today, the Iphone X. You can use the case to host your real phone if you want, or order a second one if you like to switch!.