I've been wondering for a while now… every once in a while I'll come across a post where the notes are not only shown in boxes below upon hover, but also in the boxes covering the original text, for example, post #2198395 or post #2290983.
However, most of the time, the text won't display in the original boxes, only in the lower boxes upon hover. For example, post #2338281.
What is it that allows/causes the text to display in the original boxes like so?