How does brave know that I just looked at my screen

Are you able to receive general desktop/push notifications?
Yes

Are you in a supported region (if so, which one)?
Yes, USA

Give us a brief description of the ads behavior you’re seeing
The Ads are working just fine, but the way they appear makes me curious.
I have noticed that the ads appear right when I get back to my unlocked computer, or walk close to it. I have experienced this for about an year now, and everytime I look back at my screen, I see an ad notification. I have experienced this on both my Windows and Mac computers.

The questions I have are:

  1. Is it using my device’s bluetooth to determine my proximity?
  2. Is it using my device’s camera to identify when I am looking at the screen?
  3. Does it detect when my mouse moves after inactivity?

Because, this could be a way a service/software could try to increase engagement with their ads, I am curious now.

What OS/Brave version are you using?
|Brave|1.19.92 Chromium: 88.0.4324.152 (Official Build) (x86_64)|
|Revision|6579930fc53b4dc589c042bec9d0a3778326974d-refs/branch-heads/4324@{#2106}|
|OS|macOS Version 11.2 (Build 20D64)|