He has developed his own little sign language for this which he demonstrates in the video. He claps his chest and/or holds his arms and hands out as if to say " TA-DA"! and when he does that ,he is expecting Fanfare!
Pretty funny. Not sure what to do now. This kid is gonna have one heck of a ego if we don't slow our roll on telling him how smart/cute/genius/awesome he is all the time. HA