Sebastian Anthony of DownloadSquad.com discovered this feature while he was reading news on The Independent. It seems to work for Stable, Beta and Developer builds of Chrome.
If the site that you are visiting has a Google Chrome extension of its own, you will be prompted to install that extension. Check it out !
It’s not a Google Chrome feature. It’s a site feature. If you view the code of that page, you can see a rule to show this alert with the same image as Google do it. If you zoomed that page, you see this alert zoomed too.
Sorry, but you was caugth.
oh ! thanks for letting me know ! so, will the site alert us in the same way if we are using firefox ?
No, it probably shows it only if the user agent is of Chrome.
So, if you change your FireFox user agent to the one Chrome has, you will see it, probably.
Anyway, idiomag.com does that, too (and “The Independent” actually uses their code).