This was given to a guitar student to help them improve their legato rhythm. Most of this is picked. This is to help establish how the flow and rhythm of the notes is supposed to sound, so when you finally play the small parts with legato you have a better chance of keeping that rhythm going instead of speeding things up as most players have a tendency to do.
Here is the Guitar Pro 6 tab for this lesson:
John Taylor - guitar and bass instructor for Mile High Shred.