You might notice it, but according to this, most people wouldn't:
>“It’s a picture of an IE7 browser running on Windows Vista in the transparent Aero Glass theme with a page containing a JPEG of an IE7 browser running on Windows XP in the Luna aka Fisher Price theme?” I pointed out.
Most people probably also have no adblocker, so are being subjected to visual overload all the time they're browsing. I could definitely see that causing them to stop noticing things, if they're already spending a lot of (possibly unconscious) effort filtering out all the ads and other distractions on a page.
>“It’s a picture of an IE7 browser running on Windows Vista in the transparent Aero Glass theme with a page containing a JPEG of an IE7 browser running on Windows XP in the Luna aka Fisher Price theme?” I pointed out.
>“Oh. Huh.” they noted.
https://textslashplain.com/2017/01/14/the-line-of-death/