I am preparing an answer for a question today and then the post is closed as dupe. So, I saw the yellow banner at the top(as usual) but with a special kind of icon.
If you want a close look
It is clear that the button is there to close the banner (the tooltip also states that).
I expect a close icon X or something similar. But this thing doesn't make sense.
Please change it.
Chrome/61.0.3163.100 on windows 10
This is how it looks in Stack Overflow