Re: re:future of signage
you seem to miss the fact that this is a digital window sign, not a plain paint and wood/plastic one.
smart window signs are starting to be equipped with a built-in camera for analytics. They are deploying it for eye tracking, viewer demographics and other such statistics. Also, some of them can even do facial recognition and change what they display based on a central database with informations about what that person likes or dislikes or, as it is in China, data pulled from their official Social Credit System ( https://en.wikipedia.org/wiki/Social_Credit_System )
That's pretty much right up the alley of GDPR.
https://www.youtube.com/watch?v=uD3067JJujY
https://www.wired.com/2007/06/eye-tracking-device-lets-billboards-know-when-you-look-at-them/