That image is called a "Favicon", and is accompanied across html sites for use in web browser. You're only seeing the Favicons when you turn your phone landscape as there is more space to show them otherwise the browser doesn't bother to show you them. It's a simple cache issue with your browser's application temp files. It's far easier to live with the incorrect Favicon than to blow out all of your app cache and stores files, which will fully reset your web browser, password, history, and all.