Out of curiosity I edited the page to put a textarea on it, so I could see what happens when you're typing a sentence and happen to use Shift 3 times: It break

Out of curiosity I edited the page to put a textarea on it, so I could see what happens when you're typing a sentence and happen to use Shift 3 times: It breaks the button. If the cursor is in the textarea, tapping Shift without any other keys will add 1 circle, but if that wasn't the 3rd one, any additional Shift will remove all the circles and they don't come back. You have to click outside the textarea and hit Shift 4 times to trigger it (the first one doesn't register any circles). It seems like they tried to prevent accidental triggers (if you have 1 or 2 circles and hit anything except Shift they all disappear, and if you hold Shift while hitting another key you don't get any in the first place), but got something slightly wrong.