The auxiliary counselor role is to periodically provide constructive counsel (privately) to elders & ministerial servants delivering assignments at the local midweek meetings, and sometimes to observe & report issues with quality of weekend public talk speakers.
You might have noticed over the decades average JWs which are enrolled in the midweek meeting program receive their study point counsel from the platform before all onlookers... however, the lead parts assigned to elders & ministerial servants are never counseled/critiqued from the stage... this is because the congregation elite get to receive counsel privately, one-on-one, from that auxiliary counselor, which is usually just a pat on the back, unless the auxiliary counselor is overzealous or has an agenda.
Most JWs live out their entire life without ever being told about these culty little secrets of WT operations.
As a JW man moves up in rank, cult life often become easier for him, and his household. For example, the coordinator of a body of elders [COBE] although the title may sound intense, actually has the easiest of all roles assigned to local elders, but he enjoys the most prominence.