All right, what are these strange little graphics that appear in my editing box every time I open it up? A new set appears each time I open the editing window, and another set appears when I open the full-screen editor, and each time I hit "preview." They appear only in the editing window, while nothing unusual appears in the preview window, or when I submit the post. It's been going on for over a week now.
These are only minorly annoying. I usually just delete them, but since they don't show up in the post anyway, there's probably no need even for that. But what are they?
Here's a screen shot of this post editing screen, previously refreshed ("previewed") twice: