I’ve also just read a good article from Jon Storm in B.A.S.S. Times [1] that mentioned a similar idea for bass. A lure deep in the mouth means fish are on the bite and may mean you can get more aggressive with your retrieve. If just the rear hook is in the jaw then they are just nipping at the bait – slow down or add pauses to your retrieve. If it is on the side of the mouth, it is likely from a reaction bite – you may need to change casting angle, or adjust color somewhat (i.e. increase visibility and/or time that the fish sees the lure).
Reference:
[1] Jon Storm “Dialing In: Deep Crankbaits with Brett Hite” B.A.S.S. Times, 44(8) (2014) 17.