Does typora-root-url only work on relative path links to images?

[xiaolinggnb]

In my test, it is so.
I'd like to know if that's really all there is to it, or if there's something wrong with the way I'm implementing it.
Here's my test.
File path:

markdown.md path: C:\Users\HONOR\Desktop\test
testDir path: C:\Users\HONOR\Desktop\test\testDir
test.txt path: C:\Users\HONOR\Desktop\test\test.txt

content in markdown.md

---
typora-root-url: C:\Users\HONOR\Desktop
---

[directory](/test/testDir)

[file](test/test.txt)

![testPhoto](/test/testPhoto.png)

And the result as photo:

As the photo show, photo found in relative path successfully, but directory found failed, so as file.

So I'd like to know if that's really all there is to it, or if there's something wrong with the way I'm implementing it.