Why do resources files in sync tree lose their extension?

Joplin 1.3.18 (prod, win32) - on win10

While trying to track down some weirdness (more on that if I can repo it) I find that in .config/joplin_desktop/resources the files all have their normal extensions - .png .jpg and so forth. Likewise in a .md export. Great.

But in the tree I do a local file system sync to, the .resource - the files for some reason don't have their type extension. And why "resources" vs ".resource"?

Is there some setting somewhere to change this?

Why does it matter? Because in trying to trim down huge resource files, I find some changes are not propogating, and some deleted things are not disappearing everywhere - and so being able to quickly see what is different between \resources and .resource matters.

[After my import from evernote, with very minor cleanup, I have 64910 resource files....]

Client ID: 861cbb6a60904cbab2eef22fad712bd7
Sync Version: 2
Profile Version: 34
Keychain Supported: Yes

Revision: 6b75485a1 (master)