There was a magid shiur in yeshiva tomchei tmimim by the name of Reb Shia Arsh. (First he was a shoichet, and once he was arguing with another shoichet, and picked up his hand and raised his finger (for emphasis), and in his excitement, injured his finger against the ceiling, and became disqualified as a shoichet, and had to become a magid shiur. He was a great gaon).
Once, he was giving a shiur, and he noticed that the talmidim were throwing glances toward the door. He realized that the Frieredige Rebbe, who was then the menahel poiel, was listening in to his shiur. The Frieredige Rebbe was his boss/supervisor, and when he realized he was listening in, he made sure to make the shiur more impressive, with pilpulim, meforshim etc.
When he finished, the Frieredige Rebbe came in and asked skeptically "eimitzer doh farshteit vos ihr redt?" (It seemed that it was impressive, but not according to their level).
