[2020] Unable to Find C:S Game Files (Mac OS X)

First of all I am not at all familiar with Mac, so maybe you've already tried this or it won't be relevant at all. But in case it could be useful, you should be able to show hidden files/folders by pressing Command+Shift+Dot

The mod also notes this part.

Note for OS X users: The "Files" directory might not exist. If it doesn't, it is safe to create it manually.

So perhaps you won't need to do anything else than just create the "Files" folder and put the images in it.