What does 154 KB on a disk mean in the Pages app screen?

When I was in my Pages app the Files app is popping up on the bottom half of the screen so I clicked on the little arrow down next to Page’s on my screen, once opened it has on On My iPhone and Get Info so I pressed Get Info. And it says that there’s 154KB on a disk. What does that mean?

I would think that it meant that it is on an external hard drive or an external disc which is not on the iPhone. I could be wrong I’m pretty sure I’m probably wrong, but I figured I’d ask.

[Re-Titled by Moderator]