Makes the skin silky smooth and gloss-like and forms a protective barrier. It is an emollient so dimethicone helps fill in fine lines and wrinkles, giving the skin a nice, plump look. 

The science: It is a polymer made of repeating subunits of silicone and oxygen. By rehydrating the skin, it plumps the skin and fills out fine lines. Variation in molecular weight and viscosity changes the texture from water-like to thick liquid

Fun fact/Other Application: In hair care it is a non-volatile (mean it stays in the hair for a long time) silicone.