Why is iTunes for Windows downloading photos from OneDrive?

I realize I can be long-winded. Here's the short version:

A.) If iTunes were syncing photos from my PC to my device, then they should be on my device. But they're not.

B.) iTunes shouldn't be synching photos from my OneDrive folder because my iCloud settings are not pointed to that folder.

As an experiment, I unblocked iTunes so that I could recreate the issue and provide even more details.

As it turns out, iTunes attempt to download photos from OneDrive is triggered when I try to sync my device to my PC... so your suggestion that it's trying to sync photos between my PC and my device has some credence. But it shouldn't. If that is what's happening, it makes zero sense. Again:

1.) The iTunes for Windows app has options to sync music, videos and ebooks. It's not supposed to sync photos. It defers to the iCloud for Windows app to do that.

2.) Even if iTunes is working in conjunction with iCloud to sync photos, it should NOT be syncing files from this specific folder, i.e. my OneDrive folder. My photo sync settings are not pointed at that folder. They're pointed exclusively at the iCloud folder on my PC.

3.) iCloud routinely syncs photos between my device and my PC in the background. It's not dependent on my opening iTunes or manually initiating a sync. So this seems to be something secondary to routine photo syncing.

4.) Bottom line, if iTunes is syncing photos from my OneDrive folder to my device, then those photos should be on my device. But they're not. I have no idea what iTunes does with them after it downloads them.

Which brings me back to my initial question: Why is iTunes doing this? Why is downloading photos from a folder that's outside of my photo sync settings? And what is it doing with them, being that none end up on my device or in my iCloud?

I don't believe that's the case.

iTunes syncs music, videos and ebooks. It doesn't sync photos. It defers to iCloud for Windows to do that.

I do have iCloud for Windows installed and have it set up to sync photos from my PC to my iCloud account / device. Two important points:

1.) iCloud's syncing photos to my device typically occurs in the background all the time. It's not dependent on my opening iTunes. However, the phenomenon I described in my Original Post is specific to the launching of iTunes.

2.) The only photos on my PC that should be synced with iCloud are those in my PC's iCloud Drive folder. That's it. Nothing else. Neither iCloud for Windows nor iTunes for Windows should be scanning my entire hard drive for photos. Yet that's what's happening. iTunes is downloading photos from my OneDrive folder, which is not linked or associated with my iClouds folder. In other words, iTunes is accessing folders other than the one it's pointed to.

Also, if iTunes were syncing photos from my PC to my device, then those photos would end up on my device. But none of the photos iTunes downloaded from OneDrive ended up on my device. (To be clear, there are photos from my PC synced to my device, but it's only those photos in my iCloud folder -- as it should be.)

Here's a screenshot of the syncing options within iTunes for Windows to show that it defers to iCloud for Windows to sync photos:

And here's an screenshot from iCloud for Windows to show that it's pointed at a specific folder... it's not pointed at my OneDrive folder:

Sorry, I know I'm longwinded, but there's one other detail I was perhaps not clear about:

The photos in question are not on my PC. They are in my OneDrive cloud storage. iTunes is triggering them to download to my PC so that I have a local copy. (Again, what iTunes does with that local copy is a mystery. It doesn't put it onto my iPhone or upload it to my iCloud. And why iTunes is looking at a folder outside the parameters of my photo sync settings is a mystery.)