Docs from Documents only open in iPhoto.

OK step by step. It sounds complicated, but just do it carefully and it's a piece of cake. First navigate to /System/Library (you will find that inside the root folder, Macintosh HD), and scroll down to Core Services. Open up Core Services by clicking on the triangle next to it. Then scroll down to CoreTypes.bundle. This is where all the icons are kept. Right click on Core Services and select Show package contents. Now that that's open, right click on CoreTypes.bundle and select Show Package Contents. Next open up Contents inside that and then open up Resources and scroll down until you see Documents Folder Icons. Double click on that and then select # 3 and hit Cmd-C to copy it.

Next, do a Get Info for the Documents folder that isn't showing the correct icon. Select the icon by clicking and holding until it's kind of highlighted. Next, just hit Cmd-V to paste in the new, correct Documents icon.

When you're all done, remember to reverse what you did in /System/Library by first using the back button and then closing any open triangles. Be sure you close up Resources and Contents and close the open CoreTypes.bundle window.

Here's a garden variety empty, untitled new folder with its Get Info window and just sitting on the Desktop where I've done this.

I don't know HOW you knew how to do that. You really are a wiz!

Actually, I first found out how to do this just by Googling it. I wasn't born knowing it. 😝

But you first have to overcome your fear of entering the dreaded /System/Library. Thing is, there's a lot of stuff in there you shouldn't be messing with, so tread carefully, if at all.