Previewing Files from the OSX Cloud Drive
The Mac Cloud Drive provides a review on remote data. It provides access to the Enterprise File Fabric File System and thereby the storage that is mapped to it.
The aim is to ensure that none of the files are downloaded to the local Mac unless the user takes an explicit action to download or view a file. Occasionally the operating system will force a download to obtain more information about the file and when this occurs there is little the Drive can do except to honor the request. This though occurs very infrequently.
By default when the Drive is installed it steps the user through turning off file previews. The reason for this is that to create a thumbnail, or preview of a file, the operating system has to have access to the file so, so to do that the OS forces the file to download. This of course negates the whole effect of having a 'cloud drive' and the reason why the user is stepped through turning previews off.
What happens if you do want to preview a file ? That is simple, just press the spacebar as you can on any file within OSX Finder. This will result in the file being downloaded, the file landing in cache, and the preview popping up.