[FIXED] [PvE] Thing called "level difference"

[Bis]

Bug description: I'm not sure if you will add this or not. But at the moment Im playing on blizzard PTR server and on legion they added something called "low level mobs or level difference" which makes a great work compare to the other things. Basically there is a difference between fighting proper level mobs and lower level mobs ex. in low level raids, dungeons which has grey or green mobs for a people. I'll add some pictures where you can see how does it work as an example. Hopefully you will add this soon c: I'll use my hunter at level 103 as an example I'll fight boss "Alysrazor" in Firelands (25 n) and mobs in Broken Isle so you guys can see the damage difference (artifact weapon 750 ilvl)
Proof:
1. Alysrazor: http://imgur.com/a/q1fYw
2. Broken Isle mob: http://imgur.com/a/dT2tt
Proof that Im on PTR: http://imgur.com/a/pgy81

[Wolther]

This was fixed today

[Quicksand]

It is called Legacy Buff and it has been fixed