Use physics before adding image to scene

Hello, I’m quite new to the library, sorry if my question sounds silly.

What’s the difference between:

function create() {
  this.physics.add.sprite(100,450,'dude');
  this.add.image(400,300,'sky');
}

And:

function create() {
  this.add.image(400,300,'sky');
  this.physics.add.sprite(100,450,'dude');
}

The image has been correctly preloaded in preload().
The first function doesn’t show the dude but only the background, while the second shows the dude and the background. Is it necessary to synchronize the game and the physics engine to add sprites? I’ve been searching some explanation for this in the documentation but I’ve found nothing.

:wave:

They’re both images.

In the first example, the sky is covering the dude.