What's the Different Between Mini-fraxel and Full -fraxel?

There is no Fraxel Mini This must be the effort by a physician to brand themselves.  there is no need for this if the doctor is practicing good medicine and obtaining great results, they can refer to Fraxel Resotre, Dual or Repair.
 

This is a new one to me.  There is no laser named the Mini or Full Fraxel.  You might be referring to the Fraxel Restore which is a non-ablative laser versus the Fraxel Repair which is an ablative laser.  The Fraxel Restore treatments are usually performed in a series of 4-6 treatments waiting a month in between whereas the Repair is a single treatment with about a week of downtime.  On the other hand you could be referring to Mini as treating a small area with Full treating a large area.