In this experimental investigation of rapid Brownian coagulation in dilute oil-in-water emulsions, the absence of deformation influence on droplet interaction and drainage is established. The result is in agreement with the theory of Brownian coagulation in miniemulsions proposed by the Borwankar-Ivanov group. As a first approximation the applicability of Smoluchowski theory to rapid coagulation in emulsions is established. Observing the weak influence of droplet deformation on rapid coagulation and taking into account Borwankar-Ivanov theory that the transition to charged droplets and lower electrolyte concentrations decreases the droplet deformation, we conclude that both slow coagulation and the reversible one cannot be influenced by droplet deformation in miniemulsions. A droplet surface is homogenous in contrast to solid particle surfaces. Thus emulsions can be used as a