Many early digital releases from 2016 were capped at 1080p with high compression. A "better" version refers to 4K (Ultra HD) remasters or files with a higher bitrate that reduce "blocking" and visual artifacts.
If you found this keyword in a forum, comment section, or as a filename, here are the most likely explanations: vixen161206elenakoshkaanotsofriendlyc better
If you are looking to upgrade your digital library, look for these indicators in the file properties: Many early digital releases from 2016 were capped