Why dont inner molecules pull the stretched soap film inwards? Soap Film Surface Tention
When we stretch the soap film (as shown in linked video), the top and bottom surfaces(shown in blue) get stretched and hence pull back with some force that we call as the surface tention.
But, aren't the inner molecules also stretched(green ones)?
Shouldn't they also be stretched and hence pull the film inwards, together with the surface molecules?

 A: The surfactant molecules at the surface are not being stretched and this isn't the reason why a surface tension exists. For more on the origin of surface tension see my recent answer to the question Reason for nature of surface tension
Anyhow, the answer to your question is that yes, as the film is stretched the water molecules inside it are pulled sideways. The result is that the film gets thinner, which should be obvious: since the total volume is constant increasing the area must decrease the thickness. But the molecules inside are not stretched in any way. They just flow in the way any liquid flows when you change its shape.
The concentration of the surfactant molecules at the surface usually remains constant. In a typical system of this sort there is an excess of surfactant in the bulk solution, usually in the form of micelles or some similar macrostructure. As you stretch the film to create new surface the surfactant molecules diffuse from the bulk to the surface to keep the surface concentration constant.
