Performance artist Bettina Banayan has conducted a number of interventions on the NYC subway, but this one, in which she frosts, decorates, and shares a cake with her fellow commuters, is my favorite. Unlike the other performances, which largely revolve around making people uncomfortable (or at least discomfited), the punchline of "Subway Cake Performance 02/11/14" is a subway car full of happy people whose life in the city has been made sweeter and friendlier.