Comment on "Faceting and Flattening of Emulsion Droplets: A Mechanical Model".

Garcia-Aguilar et al. [1] have shown that the deforma- tions of “shape-shifting droplets”, reported in a series of experimental papers spawned by Refs. [2, 3], are consis- tent with an elastic model. Here we show that the inter- play between surface tension and intrinsic curvature in this model is mathematically equivalent to a physically very different phase-transition mechanism of the same process described previously [4, 5]. Hence, the models cannot distinguish between the two mechanisms, and it is not possible to claim that one mechanism underlies the observed phenomena without a more detailed compari- son of the predictions of both mechanisms with experi- ments. We suggest that the increasing number of seem- ingly contradictory experimental results indicates that the two systems [2, 3] are different. The observed “shape- shifting” processes are therefore likely to be similar out- comes of two very different physical mechanisms