Auto identify different pixels from 2 layers in order to "auto-select". Possible?

Hi

I just made these 2 images in order to try to explain the concept.

It's a simple simulation for test purposes, ok? Not a real situation yet.

Look at these 2 images:

First (just background):

Second (background with "objects" and it's shadows):

These 2 images/illustrations has exactely the same background...no light difference, no resolution difference, no color difference. The unique (at least visual) difference between these 2 images is the little shoes and it's simulated shadows.

In a reduced thinking... or thinking in a pixel grid (raster), the second images has some different pixels more or less in the center of the canvas. But the rest of the image is identical.

In this condition, I was wondering if there's any Photoshop feature that could automatically identify these "different" pixels, then select them or maybe "isolate" them?

I first tried putting each image in a Photoshop layer, then using blend modes to see any result, but no one gave exactelly the result. Also tried to make a smart layer/object from the 2 normal layers, then using stack modes, but no one also achieved too much.

Again, it's just a test...I know there are various Photoshop cutting and removing pixel's tools, including Adobe Sensei's power...

But I was wondering this technique: if having such feature, maybe in a studio, with a controlled light, temperature and professional camera settings, I could first take a photo from the background, after take a new photo with any inserted object (like a shoes!!). Despite the shadows of the object (that I'd need to solve manully after), this would make easier to isolate and cut objects or other photo elements.

Any thought?

Thank you a lot 🙂

Gustavo.