[refulgentis]

Difference being, the face is the content, the background is noise. Here, the screenshot is the content. Ex. The only physical feature of my face i like is my eyes. Yet, it'd be weird if I depth of field'd everything but my eyes.

I'm sure this has uses but it's hard to argue it does from fundamentals of photography

[probabletrain]

Its real use is the few hours of fun I had making it, this is really a toy

[stetrain]

There are lots of cases, especially in say marketing images, where the entire screenshot is not the content. You may want to highlight a specific bit of UI while still keeping the general background context instead of cropping into a small image.

This lets you click a portion of the screenshot to bring into focus.

At the end of the day it's a fun toy web app, but I don't think the general concept is useless.

[refulgentis]

Agreed, for the crowd, c.f. "I'm sure this has uses"

[AlecSchueler]

You can highlight certain elements of a screenshot.

[jprete]

I hadn't actually seen the demo when I commented! I'd assumed it was using an AI model to estimate distance from camera of the elements of a photograph and then reproducing a shallower depth-of-field. So my comment isn't all that relevant.