In our 2015 Nature Communication paper, we have provided a force-based argument to explain the drop motion. A recent paper in PNAS claimed our theory to be flawed on the basis of an energy-dissipation-based argument. In this paper, which is a Letter to the Editor, we showed that the claim of this PNAS paper was false and the models based on energy dissipation or on force balance are equivalent. This work is in collaboration with Prof. Das’ postdoc group at University of Twente.