Frankly, I just learned about the exposure setting after watching those videos.
When you tap to focus on an item, the box should appear with a sun beside it, you can draw your finger up to increase the exposure, you'll see the sun move up in relation to the box.
When you tap to focus on an item, the box should appear with a sun beside it, you can draw your finger up to increase the exposure, you'll see the sun move up in relation to the box.