How Download Image function really works?

Anyone knows how download image really works?
It says its an asyinc process. But what happens when it downloads the image?
Is it saved on disk? ( I think not). or is it stored in memory?

Thinking that it’s indeed stored in memory, I have a setup to download the images and save in an array.
After using the images, I CLEAR the array. It works fine.
However, when trying to use Download Images again to populate the same - now empty - array,
it doesnt work. All images are downloaded by they are all white.

My guess this is something related to how the Download Image function works.

Does anyone have some guidance about this?

EDIT: After digging the code I found that the functions runs on Render Thread. And uses something called ImageWrapper.
I still can’t explain why the images are white the second time I download.