Not a technical explanation but a story about a similar thing: https://www.wired.com/2009/09/russian-billionaire-installs-anti-photo-shield-on-giant-yacht/ htt

Not a technical explanation but a story about a similar thing: https://www.wired.com/2009/09/russian-billionaire-installs-anti-photo-shield-on-giant-yacht/ https://www.wired.com/2009/09/russian-billionaire-installs-a... I remember this article as the first time I learned that photo-taking can actually be detected. Given that it was written in 2009, I imagine that the general camera-detecting technology has been mostly figured out by now.