Jai Srila Prabhupada!
When a disciple very perfectly makes progress in spiritual life, this gladdens the spiritual master who then also smiles in ecstasy thinking, ” How successful my disciple has become!” He feels so glad that he smiles as he enjoys the progress of the disciple, just as a smiling parent enjoys the activities of a child who is trying to stand up or crawl perfectly.
CC Adi 7.82