iPad Camera Big Yellow Rectangle

Okay I am not talking about the little yellow square of focus, I think this is a different thing.

I was watching some online video and taking photos with my iPad when I notice a huge yellow rectangle, I would like to know what is it, does anyone knows?

It appears very fast (like 1-2 seconds) and then it goes away. I had the change to take a fast printscreen to show you, here is the image:

I notice that it was appearing when there was some movement on that part of the screen, is this live tracking movement? :o

What feature is that? and what does it do? It auto focus on that zone? Is this something that is only available at the stock camere app I guess right?

EDIT: Also I tried to disable the Live function, that upper right first button and the yellow rectangle still shows! weird, it's okay for me, I would just like to understand what is it, thanks!

Thank you!

Solution 1:

That's the face recognition at work.

Yellow rectangles are drawn around any detected faces to inform you that the facial colour/exposure/etc optimisations are in operation. The rectangle doesn't guarantee focus since there could be multiple faces detected. It's a feature of the stock camera app.