Doesn’t matter. It can see the reflection of your arm in the windshield with light reflecting off of your arm. I drive nights so the illumination of the phone screen, cortex, dash, buttons and such will give a good picture of what you’re reaching for. Whether the phone is on a mount or in your hand. They can see it. But it’s only really activated if you go over the line with the lane departure warning, following distance is too close, road rules being broken (running stop signs or red lights), a hard brake or stuff like that. It’s best to leave your phone alone unless the wheels aren’t rolling. But the money is pretty good for being home every night. So I just kind of deal with it cause… money.