Yin Feng, the Wings of Coffee: about his Coffee Entrepreneurship

As usual, Yin Feng was having dinner at Coffee Wing's Shimao department store in Beijing, when a waiter came to her and told her: boss Yin, a guest wants your autograph, like a college student. Yin Feng went out to have a look. A college student who had just graduated for half a year wanted to ask Yin Feng to sign his diploma. How can this work? How can a certificate as serious as a graduation certificate be signed?