Some annoying icons have been sticking on my banner for quite some days. I know what they are. They are from a Firfox add-on, Dictionary Tooltip, which I like very much.
I thought it’s a bug of the add-on. But it still existed when I’d disabled the add-on. And it also showed up in IE, which meant it has nothing to do with Firefox add-on.
Finally, I found the source were the posts! When I was editing the post, I accidentally double-clicked some words, which made the icon show up. The icons stayed in the post as images. The tricky thing is, the icons in post contents somehow strewed on the banner. That misleading look make me search the header css, in vain of course.