What the hold-over arrows on icons in Finder do?

What exactly do these hold-over arrows in OS X 10.9 do?

When I mistakenly press on the right arrow, it just starts flashing/blinking, and the other arrow — the left one — appears to indicate that it's now available, too. Yet nothing at all happens, not even any kind of title or annotation is provided.

The right arrow stops blinking and the left stops being bold if you navigate away from the folder, and then go back.

These arrows are really annoying; more worryingly, I'm afraid they're doing something bad behind my back. How do I turn all of this nonsense off for good?

Also, if mistakenly pressing them may have caused any damage I haven't noticed yet, how do I undo any such damage?

It just changes pages on the icon preview for multi-page documents.

Not spectacularly useful with small icons like that, but if you have huge icons set or are in column or cover-flow view, it's a quick way to see what's actually in the document without opening them.

If you click away from the icon, it goes back to the first page, so it doesn't actually change anything.

You can turn it off by using this command in the Terminal:

defaults write com.apple.finder QLInlinePreviewMinimumSupportedSize -int 514

If you want it back, change the value 514 to 0.