Personality
Reb Zalman Moishe was known for his sharp and even crude style of rebuke during farbrengens. However, those who knew him well understood that the "real" Reb Zalman Moishe was refined and considerate. Nevertheless, he used this approach at farbrengens because he believed that then is the appropriate occasion to deal with the animal soul, which understands no other language.
When he arrived in Tel Aviv, some elderly Chassidim there were upset at Reb Zalman Moishe’s sharp style of farbrengens. They wrote a letter of complaint to Rabbi Yosef Yitzchok Schneerson, who replied, saying that their letter caused him “great pain and much sorrow of the spirit,” and completely dismissed their complaints.
A characteristic episode is told concerning his sense of submission to the Chabad Rebbes: The Rebbe Rayatz once turned to him at a farbrengen and said something to him. Afterwards, the other Chassidim asked him what the Rebbe had said. "I didn't hear one word," he responded, "only one thought bothered me at that moment: When will the Rebbe already remove his holy eyes from my disgraceful face?"
Read more about this topic: Zalman Moishe Ha Yitzchaki