Upload the highest resolution version of a file you think you will ever need.
MediaGraph gives you the ability to restrict access to a file based on a user’s Group and/or Role. So there’s typically no need to upload multiple versions of a file. Having large files in the MediaGraph account reduces the need for any special delivery of files when a large version is needed.
It’s best to use the native size of the file. Do this by leaving the Resize box unchecked.