it is possible that one of the apps on your phone is a trojan,
and is creating a generic "red herring" in order to hide what it's really doing.
it also is possible that this is just some Google keep-politically-correct-images-available stuff, and those images are part of your Android's current install, or part of another app's current install, and your Android is seeing those images, & is thumbnailing them.
Either way, I think it's Android doing it, not some app you installed ( Google's photos app, is most likely culprit )
Maybe a reverse image search, or a search for the filenames? Might turn up something.
Other than, I agree with the suggestion of limiting file permissions and trying to identify it that way. Or maybe you could open your phone in safe mode and try opening apps one by one to see which one triggers the folder creation.
Also, where in the folder structure is the Cache folder appearing?
Opening an app doesn't cause the cache folder to be created. I have been through the apps twice and the folder has not appeared.
I deleted the folder around 1500 today and it came back at around 1700 according to the folder and file creation times. But I wasn't using my phone at that time.
I generally don't trust the permissions boxes as there are some apps like Smart Audiobook player or Files which do have access to the file system but show No permissions granted in the app info.
as for the location of the folder it is in the root user directory along with DCIM, Downloads, and Documents folders.