Mime does not recognize JFIF files
After doing some research on this file type and perusing our upstream: https://github.com/file/file/blob/master/magic/Magdir/images#L1264
This is the determination.
JFIF is a file interchange format, meaning to us that it can contain any JPEG type format. Most importantly, this file type should be handed to the systems JPEG processing software for use. This leads us to believe associating this file extension with image/jpeg
is the correct change.