Guru Maharaj always said, "You are acting as a Guru because you are sitting in front of me, and that is forcing me to think about Mahaprabhu and speak. That is what my Guru Maharaj ordered, and you are facilitating that – this is Guru Karya. Guru Karya means the work of Guru which you are doing.”
I also heard Guru Maharaj say on Ramnavami day that His Guru Maharaj said, "Shishyas also act as Guru, because they always observing the activities of their Guru, and sometimes their Guru may forget Anhik, so the shishya will tell Gurudev, It's Anhik time."
—Rasabihari Das, Jammu